Posted by T.Gracken on November 10, 2002 at 19:27:19:
In Reply to: derivatives posted by Tim on November 10, 2002 at 17:22:07:
: i've been trying to find dy/dx of x^3(2x-5)^4 for quite some time now. i've worked many different ways but nothing seems right. we just learned the power chain rule, but im still lost.
you must use a combination of rules.
start with the product rule (since you are multiplying things), then use power rule.
note that you have x^3(2x-5)^4
so you have a product of x3 and (2x-5)4
so Dx[x^3(2x-5)^4]
= x^3*Dx[(2x-5)^4] + (2x-5)^4*Dx[x^3]
where Dx[y] means the derivative of y with respect to x.