How do you differentiate #f(x)=3x(2x+1)^3 # using the product rule?

1 Answer
Apr 15, 2018

#=>f'(x) = 3(2x+1)^2(8x+1)#

Explanation:

#f(x) = 3x(2x+1)^3#

#f'(x) = d/(dx)[3x] (2x+1)^3 + 3xd/(dx)[(2x+1)^3]#

#f'(x) = 3 (2x+1)^3 + 3x(3)(2)(2x+1)^2#

#=>f'(x) = 3 (2x+1)^3 + 18x(2x+1)^2#

If you wish to simplify at all, there is some factoring:

#f'(x) = 3(2x+1)^2[(2x+1)+6x]#

#=>f'(x) = 3(2x+1)^2(8x+1)#