# Math Help - Some Derivative Help

1. ## Some Derivative Help

Just need a line by line for how to find the derivative of -

6(2x-9)^5 and x^-4+(x^3-4)^-2/5 thanks

2. Originally Posted by TneedsHelp
Just need a line by line for how to find the derivative of -

6(2x-9)^5 and x^-4+(x^3-4)^-2/5 thanks
Do you know how to use the chain rule?

$\frac d{dx}\left[6(2x-9)^5\right]$

$=30(2x-9)^4\frac d{dx}\left[2x-9\right]$

3. 6(2x-9)^5

Alright, you have the chain rule here, so..

the exponent comes down, the polynomial's exponent is subtracted by 1, and you take the inside of the parenthesis' derivative and multiply it

5(6(2x-9)^4) (2)

everything else remains unchanged.

x^-4 is the same principle as up above. think of it as (x)^(-4)

(x^3-4)^-2/5
the exponent comes down, polynomial's exponent is subtracted by 1, and you take the inside of the parenthesis' derivative and multiply it

(-2/5)(x^3-4)^(-7/5)[(3x^2)]