Welcome, Guest: Register On Nairaland / LOGIN! / Trending / Recent / New
Stats: 3,151,544 members, 7,812,707 topics. Date: Monday, 29 April 2024 at 05:48 PM

CALCULUS: Please Help! Mathematicians In The House. - Education - Nairaland

Nairaland Forum / Nairaland / General / Education / CALCULUS: Please Help! Mathematicians In The House. (2202 Views)

Mathematicians In The House Should Solve This Problem / Mathematicians In The House, Kindly Solve This Linear Algebra Question / Mathematicians In The House. I Need Your Help On Mensuration (2) (3) (4)

(1) (2) (Reply) (Go Down)

CALCULUS: Please Help! Mathematicians In The House. by PigMeat: 2:25pm On Nov 22, 2016
Greetings Mathematicians in the house. I have been having this difficulties in the problem below. Please help me out!

Discontinuity and continuity of a function.
X^2-81/x-9, (the square of X, minus 81, all over X-9) show that it is a removable continuous function.
Re: CALCULUS: Please Help! Mathematicians In The House. by hammmedb: 2:31pm On Nov 22, 2016
Use quotient rule
Re: CALCULUS: Please Help! Mathematicians In The House. by Gydion(m): 2:48pm On Nov 22, 2016
L'hopital rule will do it
Re: CALCULUS: Please Help! Mathematicians In The House. by PigMeat: 2:59pm On Nov 22, 2016
hammmedb:
Use quotient rule
Thanks for the suggestion bro, buh the problem is about continuity of a function, not the derivative.
Re: CALCULUS: Please Help! Mathematicians In The House. by PigMeat: 3:00pm On Nov 22, 2016
Gydion:
L'hopital rule will do it
How bro? Please help me do it.
Re: CALCULUS: Please Help! Mathematicians In The House. by NDSMELODY(m): 4:15pm On Nov 22, 2016
L'hopital rule wont work since we are not given any limit......firstly what is continuity of a function?
Re: CALCULUS: Please Help! Mathematicians In The House. by NDSMELODY(m): 4:28pm On Nov 22, 2016
To the poster of the question you did not give us limit to work with,provided the limit is given just subtitute it into the function of x given,if the function of x is equal to 1 the function is said to be continous but if the function of x does not equal to 1 it is said to be discontinous function
Re: CALCULUS: Please Help! Mathematicians In The House. by Gydion(m): 5:16pm On Nov 22, 2016
Snap the question and lemme solve it
Re: CALCULUS: Please Help! Mathematicians In The House. by WalkerMichael(m): 5:18pm On Nov 22, 2016
Write down the question on a sheet of paper and snap then attach
Re: CALCULUS: Please Help! Mathematicians In The House. by Efewestern: 6:22pm On Nov 22, 2016
Your question is not complete.. Snap it .. Also provide the limit.
Re: CALCULUS: Please Help! Mathematicians In The House. by PigMeat: 6:50pm On Nov 22, 2016
NDSMELODY:
To the poster of the question you did not give us limit to work with,provided the limit is given just subtitute it into the function of x given,if the function of x is equal to 1 the function is said to be continous but if the function of x does not equal to 1 it is said to be discontinous function
From the question x approaches 9. Thanks for the correction. If I equate 9 for X it will be zero and discontinued. But they say show that it is a removable and a continuous function, thank.
Re: CALCULUS: Please Help! Mathematicians In The House. by PigMeat: 7:00pm On Nov 22, 2016
Efewestern:
Your question is not complete.. Snap it .. Also provide the limit.
Limits as X~>9
Re: CALCULUS: Please Help! Mathematicians In The House. by Efewestern: 7:23pm On Nov 22, 2016
PigMeat:

Limits as X~>9

okay, Let's do some mathematics..

You have X^2-81/ X - 9 = X^2 - 9^2/ X - 9

= (X - 9) (X + 9) / (X - 9)...... (1)

= from eqn 1, (X-9) will stroke out the denominator (X - 9) so we are left with

(X + 9)

At lim x-> 9 X + 9

= 9 + 9 = 18.

grin , Mathematicians in the house please correct me if am wrong.. we are all learning..
Re: CALCULUS: Please Help! Mathematicians In The House. by coobboy(m): 7:26pm On Nov 22, 2016
Lim x^2-81. (X-9)(x+9)
-------- = ------------
X - 9 X-9 The x-9 cancels
X--> 9

Lim x --> 9 (9+9) = 18
As x tends to 9 on x - 9 it's discontinuity is on 18
Re: CALCULUS: Please Help! Mathematicians In The House. by Efewestern: 7:29pm On Nov 22, 2016
coobboy:
Lim x^2-81. (X-9)(x-9). Lim (x-9)
-------- = ------------ =. X--> infinity =. Infinity As x tends to infinity on x - 9 it's infinite
X - 9 X-9
X--> infinity


How is X infinite... ?
Re: CALCULUS: Please Help! Mathematicians In The House. by coobboy(m): 7:30pm On Nov 22, 2016
Efewestern:


How is X infinite... ?

It's a limit question as x goes to infinity
Re: CALCULUS: Please Help! Mathematicians In The House. by PigMeat: 7:34pm On Nov 22, 2016
Efewestern:


okay, Let's do some mathematics..

You have X^2-81/ X - 9 = X^2 - 9^2/ X - 9

= (X - 9) (X + 9) / (X - 9)...... (1)

= from eqn 1, (X-9) will stroke out the denominator (X - 9) so we are left with

(X + 9)

At lim x-> 9 X + 9

= 9 + 9 = 18.

grin , Mathematicians in the house please correct me if am wrong.. we are all learning..

So the limit is continued at 18?
Re: CALCULUS: Please Help! Mathematicians In The House. by Efewestern: 7:36pm On Nov 22, 2016
coobboy:

It's a limit question as x goes to infinity
X tends to 9 not infinity
Re: CALCULUS: Please Help! Mathematicians In The House. by Efewestern: 7:39pm On Nov 22, 2016
PigMeat:

So the limit is continued at 18?
No its discontinous.. When you solved it wat was your answer. ?
Re: CALCULUS: Please Help! Mathematicians In The House. by PigMeat: 7:44pm On Nov 22, 2016
coobboy:
Lim x^2-81. (X-9)(x-9) -------- = ------------ X - 9 X-9 The x-9 cancels X--> infinity
infinity = Infinity As x tends to infinity on x - 9 it's infinite
The part B of the question said find the limit if it continous.
Re: CALCULUS: Please Help! Mathematicians In The House. by firstclassmumu: 7:55pm On Nov 22, 2016
God give me brain na make me too fit contribute for dis kain tin. Una weldone oooo.



I
Know
Even
Know
Where
To
Start
From

4 Likes

Re: CALCULUS: Please Help! Mathematicians In The House. by PigMeat: 8:56pm On Nov 22, 2016
Efewestern:


No its discontinous.. When you solved it wat was your answer. ?
I have not solved it. It a problem for me.
U mean it is discontinued at 18? So what is the continuity in it? How do u go abt that?
Re: CALCULUS: Please Help! Mathematicians In The House. by NDSMELODY(m): 10:34pm On Nov 22, 2016
Subtitute 9 in the equation we get 0/0 which is indeterminate ......9^2-81/9-9 = 0/0 now we can use l'hopital rule by differentiating the numerator and denominator of the function then we have 2x-0/1-0 = 2x then subtitute limit as x->9 which gives 18.........so the function f(x) is said to b discontinous since f(x) is not equal to 1.

1 Like

Re: CALCULUS: Please Help! Mathematicians In The House. by Godwinfriz(m): 10:43pm On Nov 22, 2016
Thank god for mathematics hmm nw hw dis tin tak help pesin directly
Re: CALCULUS: Please Help! Mathematicians In The House. by Sandydayziz(f): 11:00pm On Nov 22, 2016
Run outta thread**
Re: CALCULUS: Please Help! Mathematicians In The House. by coobboy(m): 11:42pm On Nov 22, 2016
PigMeat:

The part B of the question said find the limit if it continous.

Okay that's even better
The answer is 18 ---- lim x-->>9 (x+9) = (9+9) =18
Re: CALCULUS: Please Help! Mathematicians In The House. by Efewestern: 7:23am On Nov 23, 2016
coobboy:

Okay that's even better
The answer is 18 ---- lim x-->>9 (x+9) = (9+9) =18


NDSMELODY:
Subtitute 9 in the equation we get 0/0 which is indeterminate ......9^2-81/9-9 = 0/0 now we can use l'hopital rule by differentiating the numerator and denominator of the function then we have 2x-0/1-0 = 2x then subtitute limit as x->9 which gives 18.........so the function f(x) is said to b discontinous since f(x) is not equal to 1.

Exactly what I solved earlier, So we all arrive at 18 right ?.. meaning its discontinuos ....

OP any more problem ?
Re: CALCULUS: Please Help! Mathematicians In The House. by Efewestern: 7:28am On Nov 23, 2016
Sandydayziz:
Run outta thread**

Godwinfriz:
Thank god for mathematics hmm nw hw dis tin tak help pesin directly

See them art students.. By there fruit we sha know dem


firstclassmumu:
God give me brain na make me too fit contribute for dis kain tin. Una weldone oooo.



I
Know
Even
Know
Where
To
Start
From

Judging from your moniker I was thinking you gonna deliver .. grin grin, So which first class are we talking about now?
Re: CALCULUS: Please Help! Mathematicians In The House. by firstclassmumu: 8:23am On Nov 23, 2016
Efewestern:




See them art students.. By there fruit we sha know dem




Judging from your moniker I was thinking you gonna deliver .. grin grin, So which first class are we talking about now?
are you talking to me?
Re: CALCULUS: Please Help! Mathematicians In The House. by PigMeat: 9:34am On Nov 23, 2016
That you all @ cooboy ndsmelody efewestern y'all contributions were really helpful
.
Here is another question
(1) Prove that limx~>0 (sinx/x)=1
(2) Evaluate limx~>0 (x^3+x^2/x^2)
Re: CALCULUS: Please Help! Mathematicians In The House. by Efewestern: 10:31am On Nov 23, 2016
PigMeat:
That you all @ cooboy ndsmelody efewestern y'all contributions were really helpful
.
Here is another question
(1) Prove that limx~>0 (sinx/x)=1
(2) Evaluate limx~>0 (x^3+x^2/x^2)

2) We have lim X-> 0 (X^3 + X^2/ X^2)

= X^3/X^2 + X^2/X^2

From indices

= X^3-2 + X^2-2

= X^1 + X^0

Remember that anything to power zero is 1 , so we have

= X^1 + 1

= lim X-> 0 0^1 + 1

= 0 + 1

= 1.

that's ur final answer.. As for number 1, will solve it when am chance. bye. grin

Correct me if am wrong oo.. grin nobody is perfect..
Re: CALCULUS: Please Help! Mathematicians In The House. by NDSMELODY(m): 1:41pm On Nov 23, 2016
Using l'hopital rule for the two question......1. Sinx/x subtitute x = 0 we get sin 0/0 = 0/0 which is indeterminate now by differentiating both numerator and denominator we get cosx/1 then subtitute x= 0 we get cos0/1 = 1/1 which gives 1


question 2.

Subtitute x = 0 we have 0/0 which
is indeterminate by finding the first derivative we have 3x^2 + 2x/2x subt x = 0 we get 0/0 again then find second derivative we get 6x+2/2 then subt x = 0 we get 2/2 which gives 1.......

(1) (2) (Reply)

JAMB 2017 UTME/Direct Entry Applications Full Registration Guideline / Awolowo V. Federal Ministry Of Internal Affairs (1962) LLR 177 / Computer Engineering Vs Civil Engineering

(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. 48
Disclaimer: Every Nairaland member is solely responsible for anything that he/she posts or uploads on Nairaland.