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#1 Re: Help Me ! » find derivatives » 2010-04-24 20:05:38

would it be the same way differentaiting the function above as this (3x + 5)^10 function?

#2 Re: Help Me ! » find derivatives » 2010-04-24 19:58:03

f(x) = x^4-4x^2+4       g(x) = x^6-4x^3+4x^2
d [f(x)g(x)] = (x^4-4x^2+4)(6x^5-12x^2+8x) + (4x^3-8x)(x^6-4x^3+4x^2)
i think i know what to do now

#3 Re: Help Me ! » find derivatives » 2010-04-24 19:49:07

x^4-4x^2+4 ? am i getting close?

#4 Re: Help Me ! » find derivatives » 2010-04-24 19:39:49

ooo
how about this?
(x^2-2)(x^2-2)
2x^4-2x^2-2x^2+4
2x^4-4x^2+4

#5 Re: Help Me ! » find derivatives » 2010-04-24 19:33:32

f(x)= (x^2-2)^2        f(g)= (x^3-2x)^2
      = (2x^4-4)               = (2x^5-8x^2)
(2x^4-4)(10x^4-16x) + (2x^5-8x^2)(8x^3)

#6 Re: Help Me ! » find derivatives » 2010-04-23 22:32:05

hey,
Do i expand the brackets before i differentiate?

#7 Help Me ! » find derivatives » 2010-04-23 22:00:24

Joker
Replies: 12

1) (x² + 2)² ÷ (x² + x-¹)³



2) (x²  + 1)² (x³ - 2x)²

#9 Re: Help Me ! » Finding x co-ordinates please help me » 2010-04-21 20:39:10

how do i find y and b ? plug -1 into the derivative ?

#10 Re: Help Me ! » Finding x co-ordinates please help me » 2010-04-21 20:20:36

like this?
3x+3=0                         x-3=0
x=-1                              x=3

#14 Re: Help Me ! » Finding x co-ordinates please help me » 2010-04-21 20:00:02

Something like this?
9 = (x-2)^2 + 2(x+1)(x-2)
9 = x^2-2x-2x+4+2x^2-4x+2x-4
3x^2=6x=9

#15 Re: Help Me ! » Finding x co-ordinates please help me » 2010-04-21 19:26:43

do i use y=4 to find the x co-ordinate?

#16 Re: Help Me ! » Finding x co-ordinates please help me » 2010-04-21 19:19:14

Am i finding the x co-ordinate of a ponit where the tangent is parallel to another tangent?

#18 Re: Help Me ! » Finding x co-ordinates please help me » 2010-04-21 19:07:05

oooo found my mistake 6x3=18 not 24 ops

#19 Re: Help Me ! » Finding x co-ordinates please help me » 2010-04-21 19:05:54

4 = (3-2)^2 + 2(3+1)(3-2)
4 = (3-2)(3-2) + (6+2)(3-2)
9-6-6+4+24-12+6-4-4= 11

#20 Re: Help Me ! » Finding x co-ordinates please help me » 2010-04-21 18:47:01

where did that equation come from? wasnt this the first derivative f'(X) = (x + 1)2(x+1) + (x-2)^2

#23 Re: Help Me ! » Finding x co-ordinates please help me » 2010-04-21 18:26:48

plug (3,4) into f'(x) = (x +1)2(x+1) + (x-2)^2?

#24 Re: Help Me ! » Finding x co-ordinates please help me » 2010-04-21 17:54:11

sry just thinking about it, i dont really get the question either the "tangent is parallel to the tangent at the point (3,4)" confuses me dont worry about i will get my lecturer the explain thx for the help.

#25 Re: Help Me ! » Finding x co-ordinates please help me » 2010-04-21 17:42:10

umm the whole question goes like this,
A) find the x co-ordinate of the points on the curve Y = (x+1)(x-2)^2 at which the gradient is zero. test whether the points are minima or maxima. this part with your help is done. thx agian
B) Also find the x co-ordinate of the point at which tangent is parallel to the tangent at the point (3,4)

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