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Travel › Re: North Cyprus by benji93: 8:10pm On Sep 01, 2015
terrywales:
ote author=benji93 post=37276576]DR WIP, I sent an appointnent request to the designated email last friday, but i am yet to receive my appointment day, pls how long does it take to get an appointment date after sending the appointment request I guess by now u should have received your appointment date..
Yes o my brother, thank you for your concern
Science/Technology › Re: Generating Electricity 2 by benji93: 11:38am On Aug 31, 2015
common how does the microphone work, the vibrations from the sound is converted to a coil changing its distance from an underlying magnet, and you know what this produces voltage induced in the coil, then this low current allows a higer current to flow through the collector of a transistor(Amplification) basically.
Science/Technology › Re: Does Electricity Works In A Vacuum? by benji93: 11:31am On Aug 31, 2015
In my opinion there is nothing like vacuum my friends, you can approach a vacuum state as much as possible, but you can never get to that state, its like vacuum, if you cannot get to a state, approximate that state to solve a problem, in my own understanding it is not possible to say that cunduction through vacuum is possible, in the case of production of electricity through DC, i think it is not possible, sice the flow of electrons depends on the connection of the atomic or molecular particles, so one single hole in an atomic species in the electrolyte initiates the process, but this cannot be possible if the atoms or molecules do not have their virtual orbitals intersecting, hence the electrons having the tendency of switching between orbitals of neigbouring atoms or molecules, for the creation of current from magnetism, there might be a possibility at high voltages, i am on tring to understand why electrons can move on the influence of magnetism.
Education › Re: Mastercard Foundation Scholarship, Enter Here by benji93:
mrdrizzy:
hi thanx for the motivational words

care to explain few things bout the admin u got

-is it for postgraduate or under?

-on METU site it was written boldly ''METU does not provide any scholarships to international students'',how den did u do urz

-does it cover all expense,ie medicals,visa,flight ticket etc?
-it seems its over this year,care to highlight how u did urs exactly.thanx
They do grant tuition reduction and exemption, 50% or 100% respectively to undergraduate students,you should have read everything in that note from which you are making a reference,but even when you obtain the grant, as soon as you begin your academics, the grant is subject to your performance. but that is seriously limited to about 10% of international students. I believe their fees(undergraduate) are quite affordable($700-$2000) moroever institutions like METU were particularly made to provide top notch science and engineering education to their citizens, so their receptance of international students was not a priority until recently but news on them indicates the trends are changing, the government is determined to increase the inflow of international students into the country, and that can only be achieved partly by offering enormous scholarships and grants. Undergraduate applications to METU is now over though,but you can google "METU international undergraduate application" to take a look at the steps if you so wish. i am not certain about graduate programs. I advice you should rummage through their official website for information, METU ankara might not offer you scholarship, but according to a brief research that i just conducted, there are so many grants that can help you study at METU(post graduate), also you can check METU North Cyprus, i think they are still admitting students. You can ask any other question, i will be willing to answer.
Education › Re: Mastercard Foundation Scholarship, Enter Here by benji93:
Un God still liveth, i almost made a resolution not to come to this forum again after my craze for obtaining a mastercard scholarship ended, thanks to U of T and Arizona State University. I knew i had a very slim chance though as i never took SAT or TOEFL, but the craze for gaining admission into a reputable institution overseas did not stop as i was tired of Substandard Engineering education dispensed here in Africa, but i still had the belief that without SAT,IELTS or TOEFL,i still would get that opportunity. So i began rummaging through the internet for every scholarship opportunity available, lo and behold, there was Middle East Technical University Ankara, Turkey, , fortunately this time there was no application fee required, so i thought, there is nothing to gain or lose, na free.hehehehe. i unfolded all information about the school, it's a reknowned government international institution,affordable fees, they accept WAEC, but they said "meeting the admission requirement does not guarantee admission", this rang a thought in my head.Another SAT, TOEFL palava, passport was not ready and i needed it to register for any of those exams.to further deepen my despair they only accept 15 international students for my desired course.I just said to myself i will make this one, no matter how difficult it is. Na so i take apply my people, but there was another advantage, i had began research, one of my research activities involved finding a detailed mathematically proof of the popular Thevenin's theorem . So i applied with my WAEC result and my first original research work, believing that it will speak in place of SAT and TOEFL, then i capped everything with God and submitted it. exactly four weeks later in June,as i was deep in anticipation , na so i check my mail, "it is our pleasure to announce to you that you have been admitted into our institution".I bet you i was launched into cloud 9.So my people,1. believe in God, 2.delete every word called "impossible" from your lexicon, this word in itself is a mountain, so if you delete it, you have moved one mountain.3. my friends please do a comprehensive search for information on opportunities, you will definitely find that singular opportunity that suits your case.4.please begin research now, research is a culture that will yield bounteous fruits in the future if you start from your secondary or undergraduate level, analyse stuffs, find the solution to problems, in fact there are a lot of questions in Science that are still unanswered,express the unknown secrets of life in literature form. maybe you will be the first person to prove that Isaac Newton was actually wrong. do not think research is reserved for Msc or Phd level, your school might not encourage it, but do it yourself. The sky is your starting point.All the best in your endeavours.
Travel › Re: North Cyprus by benji93: 8:57pm On Aug 24, 2015
If i want to apply to METU NC what do i send to you and what is your email address?
Travel › Re: North Cyprus by benji93: 9:27am On Aug 24, 2015
DR WIP, I sent an appointnent request to the designated email last friday, but i am yet to receive my appointment day, pls how long does it take to get an appointment date after sending the appointment request
Travel › Re: North Cyprus by benji93: 6:32pm On Aug 04, 2015
Dr WIP , i am getting ready to visit the turkish embassy at abuja, for my turkish visa, i have a sponsor's letter(with the letter head of his company), his bank statement for the last 6 months and a photocopy of his passport, will that suffice the sponsor's requirement.Thank you in advance.
Travel › Re: North Cyprus by benji93: 4:41pm On Jul 17, 2015
wip7:
hmmmm I am assuming the person you spoke with is either a newbie, lost or clueless regarding your request. The university in this region dont send emails to embassy. The details sent goes via 2-3 channels right from the university to the embassy. In most cases (93%), it goes via the local authority (ministry or embassy in turkey) and they communicate directly with Turkish embassy Abuja or elsewhere. Or a double fax-system is used especially in case of METU.

One question is have you made your payment? if you have made your payment, the right person in METU will dispatch your details via the right channels to Abuja if you have earlier collected your originals from Nigeria.
Dr WIP, i appreciate your information, but with regards to payment, The registration guide sent to me through post specifically directs prospective students not to pay any fees until they arrive on campus, i am even surprised they sent me an admission package(Including the Official Acceptance letter on) through post without having to pay anything. The acceptance letter also does not bear any amt that i must pay, It only expresses that i have been admitted and that i should book a place in the dormitory as soon as possible(information in English and Turkish) and We are happy to welcome you to our University for the Next couple of years. I do not know if that works at METU NC.Infact application by international students to METU Ankara is free for this Academic Year, whereas I have to pay an application fee for METU NCC, unless i apply through people like you.Prior to obtaining a copy of the registration guide, i asked an academic advisor, and she told me that i cannot pay the fees until september. She told me particularly. Get your Visa and come for registration on the 14th of september. and when i checked their website there was no information concerning payment of school fees during Visa Application.The information was take your Acceptance letter and get your visa at the turkish embassy in your home country. Even the 2015/2016 Academic year tuition fees is yet to be fixed, it's a public university, so the ministerial board of turkey will decide that at a later date.I do not know if you understand my expresses, but i am telling you exactly what their guide provided and maybe The system of METU ankara, and the likes is different from the private universities in Turkey, and Schools in North Cyprus which you are particularly specialized in.And my little research also informed me that METU ankara admits very few International students, the total quota for international degree seeking students is 295. After surfing through this thread and other threads i have not found anyone that genuinely claims that he is a student of METU ankara,but if you are providing information based on the fact that you know how one METU Ankara Student applied and obtained his Visa,you should tell me. Notwithstanding i appreciate all you are doing here.Thank you
Travel › Re: North Cyprus by benji93: 12:23am On Jul 16, 2015
Dr WIP , Please Is <embassy.abuja@mfa.gov.tr> the related email of the turkish embassy in Nigeria that METU ankara International Student office has to send my acceptance letter and admission notice to? Hoping to hear from you soon Sir.
Travel › Re: North Cyprus by benji93: 7:09pm On Jul 14, 2015
Dr WIP, thank you once again, I have contacted METU ankara International student office and they told me that i should send them the email of the related office of the Turkish Embassy in Nigeria, so they can send them my acceptance letter. So what do u have to say about this Sir?
Travel › Re: North Cyprus by benji93: 8:36pm On Jul 13, 2015
wip7:
I have replied you above correctly. If you wish to apply for visa in Turkish embassy in Ghana, you can do that provided you have legal residence permit in Ghana. You will email or call your chosen University to send your details to Turkish embassy in Ghana.

If you want Turkish embassy in Nigeria. Kindly inform them also. Since they are not wizard/witchcraft most of them believe by default that Nigerian holding Nigeria passport lives in Nigeria by DEFAULT. But if you dont live in Nigeria, then re-set them by telling them where you want the details to be sent to.

NOTE: the details I referred to above, means copy of your acceptance letter, payment details if any, submitted docs during application...........all goes to embassy in order to attend to you.
Thank you so much Sir, you have been of great help.
Travel › Re: North Cyprus by benji93: 6:54pm On Jul 13, 2015
wip7:
You can choose where to send it to provided you have legal residence. If you are living legally (documented) in Ghana and wants to apply in Ghana...you will inform your university to send the details to Turkish embassy in Ghana and it will be done. We do that for our own students that live elsewhere, so is not an issue!
Thank you Dr WIP, but u miscontrue something, i have been admitted into METU ankara, and i have received the acceptance letter both my email and post, but i completed my secondary school in Ghana, and wrote WASSCE in Ghana, when i was applying, a section of the application directed me to fill in my nationality and place of birth and i did that accordingly(Nigeria and Lagos), another part directed me to fill in a contact address where i would like the to send me the letter of acceptance,and i provided one, but i did not specifically inform them i wanted the acceptance letter to be sent to the turkish embassy in Ghana.So please what do u have to say concerning this Sir?
Travel › Re: North Cyprus by benji93: 4:37pm On Jul 13, 2015
Good day Dr WIP, i appreciate your previous reply.I am a prospective student of METU ankara, but i live in Ghana, if METU has sent my acceptance letter to the embassy, would it be the Turkish Embassy in Ghana or Turkish embassy in my home country Nigeria
Travel › Re: North Cyprus by benji93: 1:59pm On Jul 01, 2015
wip7:
For Turkish embassy, the relationship does not really count unlike Cyprus embassy/consulate that you either must be the sponsor or your parents.

Meanwhile your dad's friends should state the extent he will sponsor you, in what capacity and possibly why he will be the one taking the role of your parents (tips; he may talk about your academic goals, educational prowess and need to augment your parents financial status). If he has sponsored you before on any project, he may include or reference that.

Not boring and long epistle, point-based may be good and not very very big English but simple and direct (dont let him show his Queens English too much...so the man wont be scared).

He should state your chosen program and duration, what kind of sponsorship he will provide (full or partial) and possibly his source of income (Chairman OANDO or Primary school teacher or whatever he is)...just in 1-2 lines will be nice.

If he owns company on the letterhead will be perfect or he may borrow letterhead from where he works to support his claims.

These are the points in my template for you. cool cool
Wish u Success!!
Thank you very much big brother, may God bless you.
Travel › Re: North Cyprus by benji93: 9:12am On Jul 01, 2015
Thank you for your previous reply Dr WIP, I am the guy that gained admission into METU, Ankara Campus. I have another issue pertaining my sponsor, my sponsor is not a parent but my father's friend. How does the relationship between i and my sponsor determine the outcome of my visa application, bearing in mind that he is ready to provide all documents necessary to prove that he will take up the responsibility of all expenses. Another thing is that he has never written any guarantor's letter before now, i have an idea of what the guarantor's letter looks like, but as a more experienced compatriot, i want you to advice me on how you think he should write the letter favourably, maybe you can provide a template in this regard, i will very much appreciate it.Thank you in advance
Education › Re: Nairaland Mathematics Clinic by benji93: 7:18pm On Jun 29, 2015
prove the intersecting chord theorem?
Education › Re: Nairaland Mathematics Clinic by benji93: 7:10pm On Jun 29, 2015
aman2:
purely for statisticians. if u really guru. prove d simpson1/3 rule n state it axiom
how much will you pay if i prove it
Travel › Re: North Cyprus by benji93: 12:23pm On Jun 20, 2015
wip7:
Yes you can apply for visa with the current acceptance letter you have. When did you apply for admission and when did you get result? Most international students application have not been evaluated....yours seems strange and too fast! Anyway you can pay towards August and book appointment with embassy. Visit Turkish embassy website for other requirements.
Dr wip, thank you for your reply, I reside in Ghana and i wrote my WAEC here too, I am talking about Middle East Technical University Ankara precisely, I applied in middle may, i was told to expect my admission decision in 4 weeks time, i got it last week wednesday.Though i was contemplating about METU NC too, and i almost applied when i got the application fee, but by his grace i got into METU ankara, and that was a choice not difficult to make because of the fairly reasonable fees of METU ankara even without any scholarship,and top notch education. The last time i contacted them about the embassy requiring the receipt of the paid school fees, i was told to go back to the embassy and tell them i cannot pay the fees until september, i think the lady thought i was already at the embassy. and i can draw conclusion that they sent a copy of the acceptance letter to the embassy as soon as i got mine. So it means that the embassy would have to understand that they could issue me the visa without paying the school fees which should be done in september, moroever registration begins in the second week of september.I am even in Ghana now, so i just want to know when it will be most appropriate to book the appointment. Or probably i should pay the embassy a visit at abuja, make the necessary enquiries while i hang around and afterwards book appointment. Also i presume that an original WAEC result is a certified one, across West Africa, but do i still have to go to the Ministry of Education of Nigeria. God bless Sir.
Travel › Re: North Cyprus by benji93: 9:22pm On Jun 19, 2015
Hello , I do not have a national ID card but i have a passport, can i still proceed with my student visa application to turkey?
Travel › Re: North Cyprus by benji93:
Hello Dr Wip, I just gained admission into METU ankara, I was sent an online acceptance letter, can i apply for a a visa with the online acceptance letter, or do i have to wait for the original which will arrive through P.O Box.Also a METU correspondent insisted that i cannot pay the tuition fees until september, prior to that i thought submiting the receipt that testifies that i have paid my fees is a visa requirement. What is your take on this and can you post up a list of the other requirements, and when it will be most suitable for me to visit the embassy thenceforth.Thank you Sir.
Education › Re: Nairaland Mathematics Clinic by benji93: 2:05am On Jun 09, 2015
hello guys i am imploring all Engineering and Physics students to join Nairaland Physics gurus, as there are certain physics questions that do not suit the purpose of this thread.I am thinking of forming an Engineering group but we can start with tish
Education › Re: Nairaland Physics Students Forum by benji93: 1:58am On Jun 09, 2015
lets get started guys
Education › Re: Nairaland Mathematics Clinic by benji93: 1:19am On Jun 09, 2015
goofyone,
you are right brother but you misstated. (1 + x)^1/x = e as x approaches 0

(1 + 1/x)^x =e as x approaches infinity.
so as u rightly did we substitute 1/2h for x
(1+2x)^1/x = (1 + 1/h)^2h = ((1 + 1/h)^h)^2 = e^2 as h approaches infinity
but as h approaches infinity x approaches 0, therefore the limit is e^2
but you have really done well by solving all these, God bless this forum
Education › Re: Nairaland Mathematics Clinic by benji93: 1:16am On Jun 09, 2015
goofyone:
| 3-x | ≥ 1, i.e. 3-x ≥ 1 & -(3-x) ≥ 1
-x ≥ 1 - 3 & -3+x ≥ 1
x ≤ 2 & x ≥ 4




x> x²
x-x²>0
x(1-x)>0
x > 0 & 1 - x > 0
x > 0 & 1 > x or 1 > x > 0. X will be numbers between 1 and 0, e.g. 1/2



Singularities at x = 1 and x = -1 define domain. Pretty much all real numbers except 1 & -1
U ( 2 , infinity ), U ( -infinity , -2 ), 0


f(secθ) - f(tanθ) = sec2θ - 1 - (tan2θ - 1)
= sec2θ - 1 - tan2θ + 1
but sec2θ = 1 + tan2θ
thus, f(secθ) - f(tanθ) = 1



f(2sinx) + f(cosx) = log(2sinx) + log(cosx)
= log(2sinxcosx) = log(sin2x), which at x=π/4, is log(Sin(π/2)) = log1 = 0


cotx = 1/tanx (derivative of same curve)
tan0 = 0
tanπ = 0
Period is π


f(x)= x+1/x
f(1/x)= 1/x+1/(1/x) = x + 1/x
if f(x) = (x+1)/x, then f(1/x) = 1/(1+x)


f(2) = 5/4
f(f(2)) = f(5/4) = (2(5/4)+1)/(3(5/4)-2)
=(5/2+1)/(15/4-2) = 4/2=2




lim (1+x)^x as x→∞ = e
x = 1/2h in equation, then
lim (1+h)^2h as h→∞ = e2, if approaching x approaching 0 from righted

you are right brother but you misstated, (1 + x)^1/x = e as x approaches 0

(1 + 1/x)^x =e as x approaches infinity.
so as u rightly did we substitute 1/2h for x
(1+2x)^1/x = (1 + 1/h)^2h = ((1 + 1/h)^h)^2 = e^2 as h approaches infinity
but as h approaches infinity x approaches 0, therefore the limit is e^2
but you have really done well by solving all these, God bless this forum
use l'hopital to find solution.
DIfferentiate top and bottom,
(-2sin2x)/(x²(-2sin2x) + 2x(1+cos2x))
differentiate again
(4cos2x)/(x²(-4cos2x)+2x(-2sin2x)+2(1+cos2x)+2x(-2sin2x))
at x=0
three terms in the denominator vanish

lim 1-cos2x/x²(1+cos2x) as x→0 = 4/4 = 1




x = 4y

lim (1+(1/y))4y as x→∞

= e4


lim 2sinx-sin2x/x^3 as x→0

if, lim (2sinx-sin2x)/x3 as x→0
using l'hopital rule...
differentiate num and denom
(2cosx - 2cos2x)/(3x2)
(-2sinx + 4 sin2x)/6x
(-2cosx+8cos2x)/6
with x = 0 (at the origin)
6/6 = 1
hence,
lim (2sinx-sin2x)/x3 as x→0 = 1

if, lim 2sinx-sin2x)/x3 as x→0, then
using l'hopital rule
lim2sinx as x→0 = 0

lim sin2x/x3 as x→0
8 cos2x/6, after differentiating twice
lim sin2x/x3 as x→0 = 8/6 = 4/3



Incomplete question



f(x) = x²/(1+x²)
d/d(x²)(x²/(1+x²))
d/du(u/(1+u)) = 1/(1+u)²
derivative is thus 1/(1+x²)²




dy/dx = 4x3-21x2
d2y/dx2 = 12x2 - 42x
d3y/dx3 = 24x - 42
at x = 2, d3y/dx3 = 6


2.2sinxcox - 2sin2x
2.sin2x - 2sin2x = 0.

Also cos2x = 1 - 2sin²x
d/dx(2sin²x + 1 - 2sin²x) = 0


y = 2arc tan√x
tan(y/2) = √x
x = tan²(y/2)
dx/dy = 2.tan(y/2). sec²(y/2). 1/2
dy/dx = 1/(dx/dy)
but, sec²u = 1 + tan²u
tan²(y/2) = x
dx/dy = 2√x(1+x).1/2
dx/dy = √x(1+x)
dy/dx = 1/(√x(1+x))




y = cosh-1(2x)
2x = coshy
2.dx/dy = sinhy
cosh²y - sinh²y = 1
cosh²y - 1 = sinh²y
sinhy =√(cosh²y - 1)

2.dx/dy = √(cosh²y - 1)
2.dx/dy = √(4x² - 1)
dx/dy = √(4x² - 1)/2
dy/dx = 2/√(4x² - 1)
at x = 2,
dy/dx = 2/√15


Even though solvable, question appears wrongly worded


y = xsinx
logxy = sinx
Iny/Inx = sinx
Iny = Inxsinx
(1/y)dy/dx = d(Inxsinx)/dx
(1/y)dy/dx = Inx.cosx + (sinx)/x
dy/dx = y.(Inx.cosx + (sinx)/x)
dy/dx = xsinx(Inx.cosx + (sinx)/x)


sec²x = 1 + tan²x
=∫(sec²x + sec²x - 1)dx
=∫(2sec²x - 1)dx
=2tanx - x + C



=x3/3 - x2/2 + 2√x + C





=arcsin(3x/2)/3 + C
make x = (2/3)sinu to solve problem

dx/du = (2/3)cosu

∫ dx/√(4-9x²) = ∫ dx/√(4-4sin²u) = ∫ (2/3)cosudu/2cosu

=∫ (1/3)du
=(1/3)u + C
=(1/3)arcsin(3x/2) + C



∫ dx/(4+x²)
using x = 2sinhu

dx/du = 2coshu
x² = 4 sinh²u

∫ dx/4+x² = (1/2)∫ (1/coshu)du = (1/2)∫sechudu
using standard tables, maybe
=(1/2)arctan(sinhu) + C
=(1/2)arctan(x/2) + C



∫(Inx/In10)²/x dx = (1/In10)² ∫ (Inx)²/x dx

u = Inx
du/dx = 1/x
dx = xdu

(1/In10)² ∫ (Inx)²/x dx = (1/In10)² ∫ (u)²/x .xdu
(1/In10)² ∫ (u)²/x .xdu
(1/In10)² (u)3/3

(1/In10)² ( (Inx)3/3) + C




Interesting solving these questions...smiley
Education › Re: Nairaland Mathematics Clinic by benji93: 1:14am On Jun 09, 2015
goofyone:
| 3-x | ≥ 1, i.e. 3-x ≥ 1 & -(3-x) ≥ 1
-x ≥ 1 - 3 & -3+x ≥ 1
x ≤ 2 & x ≥ 4




x> x²
x-x²>0
x(1-x)>0
x > 0 & 1 - x > 0
x > 0 & 1 > x or 1 > x > 0. X will be numbers between 1 and 0, e.g. 1/2



Singularities at x = 1 and x = -1 define domain. Pretty much all real numbers except 1 & -1
U ( 2 , infinity ), U ( -infinity , -2 ), 0


f(secθ) - f(tanθ) = sec2θ - 1 - (tan2θ - 1)
= sec2θ - 1 - tan2θ + 1
but sec2θ = 1 + tan2θ
thus, f(secθ) - f(tanθ) = 1



f(2sinx) + f(cosx) = log(2sinx) + log(cosx)
= log(2sinxcosx) = log(sin2x), which at x=π/4, is log(Sin(π/2)) = log1 = 0


cotx = 1/tanx (derivative of same curve)
tan0 = 0
tanπ = 0
Period is π


f(x)= x+1/x
f(1/x)= 1/x+1/(1/x) = x + 1/x
if f(x) = (x+1)/x, then f(1/x) = 1/(1+x)


f(2) = 5/4
f(f(2)) = f(5/4) = (2(5/4)+1)/(3(5/4)-2)
=(5/2+1)/(15/4-2) = 4/2=2




lim (1+x)^x as x→∞ = e
x = 1/2h in equation, then
lim (1+h)^2h as h→∞ = e2, if approaching x approaching 0 from righted

you are right brother but you misstated, (1 + x)^1/x = e as x approaches 0

(1 + 1/x)^x =e as x approaches infinity.
so as u rightly did we substitute 1/2h for x
(1+2x)^1/x = (1 + 1/h)^2h = ((1 + 1/h)^h)^2 = e^2 as h approaches infinity
but as h approaches infinity x approaches 0, therefore the limit is e^2
use l'hopital rule to find solution.
DIfferentiate top and bottom,
(-2sin2x)/(x²(-2sin2x) + 2x(1+cos2x))
differentiate again
(4cos2x)/(x²(-4cos2x)+2x(-2sin2x)+2(1+cos2x)+2x(-2sin2x))
at x=0
three terms in the denominator vanish

lim 1-cos2x/x²(1+cos2x) as x→0 = 4/4 = 1




x = 4y

lim (1+(1/y))4y as x→∞

= e4


lim 2sinx-sin2x/x^3 as x→0

if, lim (2sinx-sin2x)/x3 as x→0
using l'hopital rule...
differentiate num and denom
(2cosx - 2cos2x)/(3x2)
(-2sinx + 4 sin2x)/6x
(-2cosx+8cos2x)/6
with x = 0 (at the origin)
6/6 = 1
hence,
lim (2sinx-sin2x)/x3 as x→0 = 1

if, lim 2sinx-sin2x)/x3 as x→0, then
using l'hopital rule
lim2sinx as x→0 = 0

lim sin2x/x3 as x→0
8 cos2x/6, after differentiating twice
lim sin2x/x3 as x→0 = 8/6 = 4/3



Incomplete question



f(x) = x²/(1+x²)
d/d(x²)(x²/(1+x²))
d/du(u/(1+u)) = 1/(1+u)²
derivative is thus 1/(1+x²)²




dy/dx = 4x3-21x2
d2y/dx2 = 12x2 - 42x
d3y/dx3 = 24x - 42
at x = 2, d3y/dx3 = 6


2.2sinxcox - 2sin2x
2.sin2x - 2sin2x = 0.

Also cos2x = 1 - 2sin²x
d/dx(2sin²x + 1 - 2sin²x) = 0


y = 2arc tan√x
tan(y/2) = √x
x = tan²(y/2)
dx/dy = 2.tan(y/2). sec²(y/2). 1/2
dy/dx = 1/(dx/dy)
but, sec²u = 1 + tan²u
tan²(y/2) = x
dx/dy = 2√x(1+x).1/2
dx/dy = √x(1+x)
dy/dx = 1/(√x(1+x))




y = cosh-1(2x)
2x = coshy
2.dx/dy = sinhy
cosh²y - sinh²y = 1
cosh²y - 1 = sinh²y
sinhy =√(cosh²y - 1)

2.dx/dy = √(cosh²y - 1)
2.dx/dy = √(4x² - 1)
dx/dy = √(4x² - 1)/2
dy/dx = 2/√(4x² - 1)
at x = 2,
dy/dx = 2/√15


Even though solvable, question appears wrongly worded


y = xsinx
logxy = sinx
Iny/Inx = sinx
Iny = Inxsinx
(1/y)dy/dx = d(Inxsinx)/dx
(1/y)dy/dx = Inx.cosx + (sinx)/x
dy/dx = y.(Inx.cosx + (sinx)/x)
dy/dx = xsinx(Inx.cosx + (sinx)/x)


sec²x = 1 + tan²x
=∫(sec²x + sec²x - 1)dx
=∫(2sec²x - 1)dx
=2tanx - x + C



=x3/3 - x2/2 + 2√x + C





=arcsin(3x/2)/3 + C
make x = (2/3)sinu to solve problem

dx/du = (2/3)cosu

∫ dx/√(4-9x²) = ∫ dx/√(4-4sin²u) = ∫ (2/3)cosudu/2cosu

=∫ (1/3)du
=(1/3)u + C
=(1/3)arcsin(3x/2) + C



∫ dx/(4+x²)
using x = 2sinhu

dx/du = 2coshu
x² = 4 sinh²u

∫ dx/4+x² = (1/2)∫ (1/coshu)du = (1/2)∫sechudu
using standard tables, maybe
=(1/2)arctan(sinhu) + C
=(1/2)arctan(x/2) + C



∫(Inx/In10)²/x dx = (1/In10)² ∫ (Inx)²/x dx

u = Inx
du/dx = 1/x
dx = xdu

(1/In10)² ∫ (Inx)²/x dx = (1/In10)² ∫ (u)²/x .xdu
(1/In10)² ∫ (u)²/x .xdu
(1/In10)² (u)3/3

(1/In10)² ( (Inx)3/3) + C




Interesting solving these questions...smiley
Education › Re: Nairaland Mathematics Clinic by benji93: 9:24pm On May 29, 2015
Mnewton:
tanx alot 6 is the answer right?
-6 is the right answer
Education › Re: Nairaland Mathematics Clinic by benji93: 11:45am On May 28, 2015
RobinHez:
wow! it was actually a Pume question from Delsu...
i just hope other people are going to come up with answers too sad
however if the question requires how many more men are needed to complete the work then it should be 225-75=150
Education › Re: Nairaland Mathematics Clinic by benji93: 6:17pm On May 27, 2015
RobinHez:
pls help..
A contractor agreeing to finish a work in 150 days, employed 75men
each working 8 hrs daily. after 90 days, only 2/7 of the work was
completed. Increasing the number of men by each working now for
10hrs daily, the work can be completed in time
A. 120 men
B. 100 men
C. 75 men
D. 150 men
i think the answer is not in,
let the number of men = n
let time = t
in this case n is inversely proportional to t,
n*t=k1
k1 = 75 * 720 = 54000
with this relationship it will take 90 men 600 hrs(60 days at 10hrs/day) to do the same work.
but k1 is directly proportional to amount of work done
k1=wk2
but since only 2/7 of the work was done, inorder to do the remaining work(5/7) which is a multiple of the first, we would need to increase k1,
k1 for 5/7 of work = ((54000*(5/7))/2/7)=135000
k1=n*t
t=60*10
k1=n*600
135000=n*600
n=225 men, note that i converted the days to hours.
i stand to be corrected
Education › Re: Nairaland Mathematics Clinic by benji93: 11:36pm On May 12, 2015
[quote author=factorial1 post=33641165]Prove and not "show" sir. [/quotI]
We can use logic gate to prove this,using 3 inputs there are 8 possibilities,but only 7 can be true when at least one input is true(A U B U C),but when this result is barred(considering all others except it), there is only one possibility(no input is right)(A U B U C)', but the possibility that all three inputs are right at the same time is one and the possibility that all three inputs are wrong at the same time is also one,the desired is just one possibility since it cannot be the former it has to be the latter.
A'nB'nC' = (AUBUC)'
I would have loved to use the truth table of logic gates to prove this but i am unable to,there are 16 truth tables in all 8 for multiplication of the inputs and 8 for the Addition of the inputs.
Education › Re: Nairaland Mathematics Clinic by benji93:
do you know that limiting h to 0 dy/dx = f(x)-f(x-h)/h, where h is change in x is valid, i mean instead of the usual dy/dx=f(x+h)-f(x)/h as h approaches O and is change in x, we can use the that above.
I stand to be corrected guys.
Education › Re: Nairaland Mathematics Clinic by benji93: 4:59pm On May 12, 2015
akpos4uall:
This problem involves differential equation
We were given an initial value as well as another value after a certain amount of time
Here is the problem once again



The flow rate can be represented as dV/dt
This is proportional to the volume V
i.e. dV/dt = kV
Where k is the constant of proportionality
dV/dt = kV



dV/V = kdt
Integrate to get
InV = kt + c
Where c is constant of integration
Applying the given conditions
When t = 0, V = 2500 &
When t = 10, V = 25
The equation becomes
InV = In2500 - 0.1tIn100
InV = In2500 - In(10)0.2t
Take exponential of both sides to get
V = 2500*(10)-0.2t
The above equation is the volume-time relationship.

Using V = 250,
Solve for t to get t = 5
Hence it'll take 5hrs for the water to reduce to 10%

When t = 1, V = 1577.4 which is 63.10%
When t = 9, V = 39.622 which is 1.585%

In a table like form, here is corresponding % left for the first ten 10hrs
Time(hrs). % left
1 63.10
2 39.81
3 25.12
4 15.85
5 10.00
6 6.310
7 3.981
8 2.512
9 1.585
10 1.000

I stand to be corrected
oh ok,you are right,in that light?

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