Question

find f ' (-3) if f(x)=x^3/5-6x

Answer 1

You'd have to use the quotient rule to find the derivative then plug -3 into the x in the derivative

Answer 2

remember the quotient rule is (as I use it) f(x)/g(x) where f(x) corresponds to the numerator of problem given and then g(x) is the denominator.

From there you can better understand how to actually set up the quotient rule to find the derivative:
f'(x)g(x)-f(x)g'(x) divided by (f(x))^2

from here you plug in what you found f(x) and g(x) to be from the problem.


Think you can get it from here?