Help w/ deriv of x(square) (x-2)to the fourth power

[lidiasaritza]

hi, i been ting to figure out this HW problem but i must be missing a step or something. i do not get the right answer. please help, i have a final tomorro based on this questions.

I need to find the derivative of the function by the chain rule

Q1.) f(x)=x(square) (x-2)to the fourth power

this is what i did, please tell me what i'm doing wrong.

Let u=(x-2)
dy/du=xsquare4(u)cube
du/dx=-2(this might be wrong)

formula du/dx=dy/du (times )du/dx

xsq. 4(u)cube (times) -2=xsq.-8(x-2)cube

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[Guest]

you do need to use the chain rule but you must also use the product rule as well

x^2 (x-4)^4

2x(x-4)^4+x^2*4(x-4)^3

2x(x-4)^4+4x^2(x-4)^3

Do you see how you must use both rules to find this derivative?

 

[tkhunny]

...and please note 3thestral3's use of this character "^" for exponentiation. It is much cleaner than the word version.