Derivative Problem-did i get it right?

[Mehgan]

Here's the problem:

Find the derivative for f(x)= (x^-2+x^-3)(x^5-2x^2)

The answer I got was:
f'(x)= (5x^5+5x^4-4x^2-4x/x^3)+(-3x^9+2x^8+6x^6-4x^5/6x^7)

Can anyone tell me if this is right? Thanks very much!

 

[Weatherkid11]

You use the product rule so (x^-2+x^-3)(5x^4-4x)+(x^5-2x^2)(-2x^-3-3x^-4) Then you simplify all that down

 

[galactus]

Is your problem:

\(\displaystyle (x^{-2}+x^{-3})(x^{5}-2x^{2})\)?

If so, you seem to have made it much more complicated than need be.

You don't need the product rule.

Just do the FOIL thing. You get \(\displaystyle x^{3}-2+x^{2}-2x^{-1}\)

Now differentiate term by term. Easy as pi.