How do you differentiate ((5x+1)^2)(2x-1)?

1 Answer
Mar 30, 2015

Use the Product Rule and Chain Rule:

f'(x)=(5x+1)^{2}\cdot 2+2(5x+1)\cdot 5\cdot (2x-1).

This can be simplified in a couple ways. Probably the most useful way is to leave it in a factored form:

f'(x)=2(5x+1)(5x+1+10x-5)=2(5x+1)(15x-4)

That way, you can quickly see the critical points of f(x) are x=-\frac{1}{5} and x=\frac{4}{15}.