Welcome, Guest: Register On Nairaland / LOGIN! / Trending / Recent / New
Stats: 3,154,749 members, 7,824,158 topics. Date: Saturday, 11 May 2024 at 01:07 AM

Nairaland Mathematics Clinic - Education (139) - Nairaland

Nairaland Forum / Nairaland / General / Education / Nairaland Mathematics Clinic (481350 Views)

Mathematics Clinic / 2015 Cowbell Mathematics Champion, Akinkuowo Honoured By School. / Lead City University Clinic Welcomes First Ever Baby Since 10 Years Of Opening (2) (3) (4)

(1) (2) (3) ... (136) (137) (138) (139) (140) (141) (142) ... (284) (Reply) (Go Down)

Re: Nairaland Mathematics Clinic by STENON(f): 8:44pm On Jul 17, 2014
[quote
author=jackpot]Let A(x1, y1), B(x2,
y2) and C(x3, y3) be the vertices of
triangle ABC. Derive the formula for the coordinates of it's
circumcentre.



Please help!!!
Tags: benbuks, doubleDx, Laplacian, dejt4u AmazingAngel, STENON,
efficiencie.[/quote] Pls i will only attach its solutiin because I may not be able to type it
Re: Nairaland Mathematics Clinic by Nobody: 8:51pm On Jul 17, 2014
did i hear my name .?

( no she didn't call you , she only mentioned your name ) ok .. better

* goes back to what he was downloading * .

#math.clinic .hibernation mood........till further notice.



pray for him ooo.. he don't solve or study his books again this days ..kinda killing him softly .

hmm..
Re: Nairaland Mathematics Clinic by Laplacian(m): 9:51pm On Jul 17, 2014
jackpot: Let A(x1, y1), B(x2, y2) and C(x3, y3) be the vertices of triangle ABC. Derive the formula for the coordinates of it's circumcentre.


Please help!!!
Tags: benbuks, doubleDx, Laplacian, dejt4u AmazingAngel, STENON, efficiencie.
general equation of a circle, x2+y2-2ax-2by+c=0, the centre is (a,b), three points on the circumference are given. This is enough!!
Re: Nairaland Mathematics Clinic by STENON(f): 9:56pm On Jul 17, 2014
[quote
author=Laplacian]
general equation of a circle, x2+y2-2ax-2by+c=0,
the centre is (a,b), three points on the circumference are given. This
is enough!![/quote] Sorry Pls....Is that the same for coordinate of Circumcentre?
Re: Nairaland Mathematics Clinic by Nobody: 10:22pm On Jul 17, 2014
Laplacian:
general equation of a circle, x2+y2-2ax-2by+c=0, the centre is (a,b), three points on the circumference are given. This is enough!!

nice hint/try sir

@ jackpot leme c what can be done , gana have the formula in matrix form or otherwise .

i'll try it . might get bk 2 u .

ur really tempting me mathematically.
Re: Nairaland Mathematics Clinic by HABRUZZY(m): 11:14pm On Jul 17, 2014
HABRUZZY: thanks alot bro have been able to sort my way round with some online guides thanks for the concern for now the only giving me headache is

In an examination in statistics Ade's mark in
standard units is 0.10.Marks are assumed to be
normally distributed.What percentage of the students
would be expected to score higher than Ade.
still here pls
Re: Nairaland Mathematics Clinic by dejt4u(m): 5:49am On Jul 18, 2014
jackpot: Let A(x1, y1), B(x2, y2) and C(x3, y3) be the vertices of triangle ABC. Derive the formula for the coordinates of it's circumcentre.


Please help!!!
Tags: benbuks, doubleDx, Laplacian, dejt4u AmazingAngel, STENON, efficiencie.

what i gt ws somehow long but i will try to type it here..

I got this by 1st finding the equation of a circle that passes through the 3points..

Let (m,n) represents the coordinates of the circumcenter..

Therefore,
m = 1/2 [(x12 + y12)(y3 - y2) + (x22 + y22)(y1 - y3) + (x32 + y32)(y2 - y1)] / [x1(y3 - y2) + x2(y1 - y3) + x3(y2 - y1)]

for the 2nd coordinate,
n = 1/2 [(x12 + y12)(x3 - x2) + (x22 + y22)(x1 - x3) + (x32 + y32)(x2 - x1)] / [y1(x3 - x2) + y2(x1 - x3) + y3(x2 - x1)]
Re: Nairaland Mathematics Clinic by johnpaul1101(m): 8:21am On Jul 18, 2014
benbuks:
your friend is ryt bro


medicine cobo. is eng , phy , bio & chem ,

unless you wanna study engr. den combo is eng. math , phy , & chem.

that's it .


don't you have a brochure ?

Nahhhh..........thanks anyway.
Re: Nairaland Mathematics Clinic by Nobody: 11:47am On Jul 18, 2014
jackpot: Let A(x1, y1), B(x2, y2) and C(x3, y3) be the vertices of triangle ABC. Derive the formula for the coordinates of it's circumcentre.


Please help!!!
Tags: benbuks, doubleDx, Laplacian, dejt4u AmazingAngel, STENON, efficiencie.

Draw lines from one vertex to a mid point. You'll do
this three times. Then get equations for each line and
solve the three simultaneous equations.
Re: Nairaland Mathematics Clinic by sundaylinus: 4:35pm On Jul 18, 2014
any mathematics guru in da house may please help me with this:
If α and β are the roots of equation 3x²+5x-8=0
Find the value of α^4-ß^4
Re: Nairaland Mathematics Clinic by dejt4u(m): 6:24pm On Jul 18, 2014
sundaylinus: any mathematics guru in da house may please help me with this:
If α and β are the roots of equation 3x²+5x-8=0
Find the value of α^4-ß^4
do it dis way,
α44 = (α²)²-(ß²)² = (α²-ß²)(α²+ß²)...diff. Of 2 squares;

simplifying further,
(α-ß)(α+ß)((α+ß)²-2αß)..

You can continue from there..
Note that: (α-ß) = (α²+ß²-2αß)1/2 = ((α+ß)²-4αß)1/2
Re: Nairaland Mathematics Clinic by sundaylinus: 10:57pm On Jul 18, 2014
dejt4u:
do it dis way,
α44 = (α²)²-(ß²)² = (α²-ß²)(α²+ß²)...diff. Of 2 squares;

simplifying further,
(α-ß)(α+ß)((α+ß)²-2αß)..

You can continue from there..
Note that: (α-ß) = (α²+ß²-2αß)1/2 = ((α+ß)²-4αß)1/2
dejt4u:
do it dis way,
α44 = (α²)²-(ß²)² = (α²-ß²)(α²+ß²)...diff. Of 2 squares;

simplifying further,
(α-ß)(α+ß)((α+ß)²-2αß)..

You can continue from there..
Note that: (α-ß) = (α²+ß²-2αß)1/2 = ((α+ß)²-4αß)1/2
dejt4u:
do it dis way,
α44 = (α²)²-(ß²)² = (α²-ß²)(α²+ß²)...diff. Of 2 squares;

simplifying further,
(α-ß)(α+ß)((α+ß)²-2αß)..

You can continue from there..
Note that: (α-ß) = (α²+ß²-2αß)1/2 = ((α+ß)²-4αß)1/2
thanks bro. But am confuse i dnt have idear on this, its an assigment pls put more light
Re: Nairaland Mathematics Clinic by dejt4u(m): 5:02am On Jul 19, 2014
sundaylinus: thanks bro. But am confuse i dnt have idear on this, its an assigment pls put more light
3x²+5x-8=0
Find the value of α^4-ß^4

do it dis way,
α44 = (α²)²-(ß²)² = (α²-ß²)(α²+ß²)...diff. Of 2 squares;

simplifying further,
(α-ß)(α+ß)((α+ß)²-2αß)....eqn*

You can continue from there..
Note that: (α-ß) = (α²+ß²-2αß)1/2 = ((α+ß)²-4αß)1/2...eqn**


putting eqn** in eqn*
(α-ß) = (α²+ß²-2αß)1/2 = ((α+ß)²-4αß)1/2 ...eqn**
(α-ß)(α+ß)((α+ß)²-2αß)...eqn*
= ((α+ß)²-4αß)1/2(α+ß)((α+ß)²-2αß) ...eqn+

ur question, 3x²+5x-8=0
a=3, b=5, c=-8,
but (α+ß) = b/a = 5/3
and (αß) = -c/a = -(-8/3) = 8/3
subtituting the values above in eqn+,
=[(α+ß)²-4αß]1/2(α+ß)[(α+ß)²-2αß)]
=[(5/3)²-4(8/3)]1/2 x 5/3[(5/3)²-2(8/3)]

you can finish that up.. Looking at this, it may lead u to complex no.. Jst note dat i² = -1
Re: Nairaland Mathematics Clinic by AlphaMaximus(m): 2:20pm On Jul 19, 2014
Re: Nairaland Mathematics Clinic by dejt4u(m): 2:32pm On Jul 19, 2014
AlphaMaximus:
Complex numbers? All u have to do is to find the roots of the given equation which are -8/3 and 1, find their fourth powers and the difference between their fourth powers! I don't see how we'll land in any "complex numbers".
yh my boss..u ar right.. But believe me if they asked you questions like this in my school nd u do it dis way.. You are jst paying with ZERO..
A question like this was asked in MTH101 exam wen i ws in part1.. And that very question contributed to the great number of F's in dat very course..
May God bless Professor S.S Okoya
Re: Nairaland Mathematics Clinic by AlphaMaximus(m): 2:41pm On Jul 19, 2014
jackpot: Let A(x1, y1), B(x2, y2) and C(x3, y3) be the vertices of triangle ABC. Derive the formula for the coordinates of it's circumcentre.


Please help!!!
Tags: benbuks, doubleDx, Laplacian, dejt4u AmazingAngel, STENON, efficiencie.
The circumcentre of a triangle is the point in the triangle equidistant from all three vertices/the point where any two perpendicular bisectors of any two of the three sides of a triangle intersect. Therefore to find the circumcentre of a triangle, we have to obtain the midpoints of two sides, their gradients and find the equations of each of their perpendicular bisectors and equate them to solve simultaneously for the x and y coordinates of the circumcenter.
To find midpoint of side AB:
(X1+X2/2 , Y1+Y2/2)<====midpoint of AB
The gradient ====>(y2-y1/x2-x1)
Therefore the equation of the parallel bisector of AB is found using:
Y-y1=m(x-x1)
Y-y1=[y2-y1/x2-x1](x-x1)........eq1
Now repeating the same procedure for line BC:
Midpoint====>(x2+x3/2,y2+y3/2)
Gradient=====>(y3-y2/x3-x2)
Equation of perpendicular bisector===>
Y-y2=m(x-x2)
Y-y2=[y3-y2/x3-x2](x-x2).......eq2
After both equations have been obtained , you simply solve simultaneously and obtain the values of x and y which are the x and y coordinates of the circumcentre.
Re: Nairaland Mathematics Clinic by AlphaMaximus(m): 2:47pm On Jul 19, 2014
Re: Nairaland Mathematics Clinic by Nobody: 6:12pm On Jul 19, 2014
dejt4u:
3x²+5x-8=0
Find the value of α^4-ß^4
do it dis way,
α44 = (α²)²-(ß²)² = (α²-ß²)(α²+ß²)...diff. Of 2 squares;
simplifying further,
(α-ß)(α+ß)((α+ß)²-2αß)....eqn*
You can continue from there..
Note that: (α-ß) = (α²+ß²-2αß)1/2 = ((α+ß)²-4αß)1/2...eqn**
putting eqn** in eqn*
(α-ß) = (α²+ß²-2αß)1/2 = ((α+ß)²-4αß)1/2 ...eqn**
(α-ß)(α+ß)((α+ß)²-2αß)...eqn*
= ((α+ß)²-4αß)1/2(α+ß)((α+ß)²-2αß) ...eqn+
ur question, 3x²+5x-8=0
a=3, b=5, c=-8,
but (α+ß) = b/a = 5/3
and (αß) = -c/a = -(-8/3) = 8/3
subtituting the values above in eqn+,
=[(α+ß)²-4αß]1/2(α+ß)[(α+ß)²-2αß)]
=[(5/3)²-4(8/3)]1/2 x 5/3[(5/3)²-2(8/3)]

you can finish that up.. Looking at this, it may lead u to complex no.. Jst note dat i² = -1


yea think u made a slight mistake . (alpha+beta)=-b/a and alpha*beta=c/a
Re: Nairaland Mathematics Clinic by dejt4u(m): 6:13pm On Jul 19, 2014
masperano:


yea think u made a slight mistake . (alpha+beta)=-b/a and alpha*beta=c/a
correct..thanks my guy..its bin very long that i do things like dis last

1 Like

Re: Nairaland Mathematics Clinic by Nobody: 6:14pm On Jul 19, 2014
AlphaMaximus:
Complex numbers? All u have to do is to find the roots of the given equation which are -8/3 and 1, find their fourth powers and the difference between their fourth powers! I don't see how we'll land in any "complex numbers".



excellent!! straightforward.
Re: Nairaland Mathematics Clinic by Nobody: 6:19pm On Jul 19, 2014
dejt4u:
correct..thanks my guy..its bin very long that i do things like dis last


yea i noticed it. you were clever to break down the expansion, that is the most challenging part in the question
Re: Nairaland Mathematics Clinic by Nobody: 6:34pm On Jul 19, 2014
jackpot: Let A(x1, y1), B(x2, y2) and C(x3, y3) be the vertices of triangle ABC. Derive the formula for the coordinates of it's circumcentre.
Please help!!!
Tags: benbuks, doubleDx, Laplacian, dejt4u AmazingAngel, STENON, efficiencie.



Stennon how are you? and Jackpot why did u steal my profile pic angry . lol. I love clever splakss(chicks). where is Doubledx(a great guy). and what of efficiencie(wanted to ask what you studied. mathematics or engineering or physics) you got the age question i threw in. you indeed have a rigorous mathematical mind. To all the generals masperano sends his greetings. between am one hell of a lazy dude else i would have been typing in solutions . may be when am less busy will start contributing. You guyz are really doing a great job. Kudos!!!

1 Like

Re: Nairaland Mathematics Clinic by jackpot(f): 7:12pm On Jul 19, 2014
benbuks:

Draw lines from one vertex to a mid point. You'll do
this three times. Then get equations for each line and
solve the three simultaneous equations.

Sir, is that not a referrence to the centroid?
Re: Nairaland Mathematics Clinic by jackpot(f): 7:18pm On Jul 19, 2014
AlphaMaximus:
The circumcentre of a triangle is the point in the triangle equidistant from all three vertices/the point where any two perpendicular bisectors of any two of the three sides of a triangle intersect. Therefore to find the circumcentre of a triangle, we have to obtain the midpoints of two sides, their gradients and find the equations of each of their perpendicular bisectors and equate them to solve simultaneously for the x and y coordinates of the circumcenter.
To find midpoint of side AB:
(X1+X2/2 , Y1+Y2/2)<====midpoint of AB
The gradient ====>(y2-y1/x2-x1)
Therefore the equation of the parallel bisector of AB is found using:
Y-y1=m(x-x1)
Y-y1=[y2-y1/x2-x1](x-x1)........eq1
Now repeating the same procedure for line BC:
Midpoint====>(x2+x3/2,y2+y3/2)
Gradient=====>(y3-y2/x3-x2)
Equation of perpendicular bisector===>
Y-y2=m(x-x2)
Y-y2=[y3-y2/x3-x2](x-x2).......eq2
After both equations have been obtained , you simply solve simultaneously and obtain the values of x and y which are the x and y coordinates of the circumcentre.
Yes, that's the basic. I need a compact formula. The type that you will just slot in the vertices and the answer will come out.
Re: Nairaland Mathematics Clinic by jackpot(f): 7:21pm On Jul 19, 2014
masperano:



Stennon how are you? and Jackpot why did u steal my profile pic angry . lol. I love clever splakss(chicks). where is Doubledx(a great guy). and what of efficiencie(wanted to ask what you studied. mathematics or engineering or physics) you got the age question i threw in. you indeed have a rigorous mathematical mind. To all the generals masperano sends his greetings. between am one hell of a lazy dude else i would have been typing in solutions . may be when am less busy will start contributing. You guyz are really doing a great job. Kudos!!!
mine had been there since 2012, me thinks. wink tongue
Re: Nairaland Mathematics Clinic by jackpot(f): 7:31pm On Jul 19, 2014
sundaylinus: any mathematics guru in da house may please help me with this:
If α and β are the roots of equation 3x²+5x-8=0
Find the value of α^4-ß^4
Clearly.
dejt4u: yh my boss..u ar right.. But believe me if they asked you questions like this in my school nd u do it dis way.. You are jst paying with ZERO..
A question like this was asked in MTH101 exam wen i ws in part1.. And that very question contributed to the great number of F's in dat very course..
May God bless Professor S.S Okoya
I see that as an injustice. I am sticking with Alpha Maximus on this one. He should demand for a methodological solution in his statement. Such questions can be posed this way. . .

''using the theory of quadratic equations, . . .''


Or


''Use algebra to evaluate. . .''
Re: Nairaland Mathematics Clinic by jackpot(f): 7:38pm On Jul 19, 2014
masperano:



excellent!! straightforward.
Surely. I write it that way and you give me an F, only God will judge you.

Why will I choose a rigorous path when there is a shorter, flawless and concise path?
Re: Nairaland Mathematics Clinic by dejt4u(m): 7:50pm On Jul 19, 2014
jackpot: Surely. I write it that way and you give me an F, only God will judge you.

Why will I choose a rigorous path when there is a shorter, flawless and concise path?
exactly..they ar so wicked in my school..more than 70% of my dept mate failed MTH in year 1 nd 2.. Yellow house suck ma GP small, na God eventually save me from them ooo..
Re: Nairaland Mathematics Clinic by jackpot(f): 8:07pm On Jul 19, 2014
dejt4u:

what i gt ws somehow long but i will try to type it here..

I got this by 1st finding the equation of a circle that passes through the 3points..

Let (m,n) represents the coordinates of the circumcenter..

Therefore,
m = 1/2 [(x12 + y12)(y3 - y2) + (x22 + y22)(y1 - y3) + (x32 + y32)(y2 - y1)] / [x1(y3 - y2) + x2(y1 - y3) + x3(y2 - y1)]

for the 2nd coordinate,
n = 1/2 [(x12 + y12)(x3 - x2) + (x22 + y22)(x1 - x3) + (x32 + y32)(x2 - x1)] / [y1(x3 - x2) + y2(x1 - x3) + y3(x2 - x1)]
That's what I got too. The final answer is also

((|BC|2)(AB.AC)+(|AC|2)(BA.BC)+(|AB|2)(CA.CB))/(2|AB x AC|2)

Please, can you express your answer in this form?

NOTE:
x is cross-product
. is dot-product
Re: Nairaland Mathematics Clinic by jackpot(f): 8:10pm On Jul 19, 2014
dejt4u:
exactly..they ar so wicked in my school..more than 70% of my dept mate failed MTH in year 1 nd 2.. Yellow house suck ma GP small, na God eventually save me from them ooo..

shiiit happens. I had my fair share too. When an intelligent student is on the receiving end, it is prejudicial.
Re: Nairaland Mathematics Clinic by jackpot(f): 8:27pm On Jul 19, 2014
Laplacian:
general equation of a circle, x2+y2-2ax-2by+c=0, the centre is (a,b), three points on the circumference are given. This is enough!!
confirm, but you see, Sir, i just need a direct proof leading to a compact formula. Haven't proved one completely yet.
Re: Nairaland Mathematics Clinic by Nobody: 8:35pm On Jul 19, 2014
masperano:



Stennon how are you? and Jackpot why did u steal my profile pic angry . lol. I love clever splakss(chicks). where is Doubledx(a great guy). and what of efficiencie(wanted to ask what you studied. mathematics or engineering or physics) you got the age question i threw in. you indeed have a rigorous mathematical mind. To all the generals masperano sends his greetings. between am one hell of a lazy dude else i would have been typing in solutions . may be when am less busy will start contributing. You guyz are really doing a great job. Kudos!!!

I'm here oga mi; it's been a long time bruv! Hope you are doing great...1luv

1 Like

(1) (2) (3) ... (136) (137) (138) (139) (140) (141) (142) ... (284) (Reply)

DIRECT ENTRY Admission. / Mastercard Foundation Scholarship, Enter Here / 2016/2017 University of Ibadan Admission Thread Guide.

(Go Up)

Sections: politics (1) business autos (1) jobs (1) career education (1) romance computers phones travel sports fashion health
religion celebs tv-movies music-radio literature webmasters programming techmarket

Links: (1) (2) (3) (4) (5) (6) (7) (8) (9) (10)

Nairaland - Copyright © 2005 - 2024 Oluwaseun Osewa. All rights reserved. See How To Advertise. 67
Disclaimer: Every Nairaland member is solely responsible for anything that he/she posts or uploads on Nairaland.