
William W. answered 03/22/22
Experienced Tutor and Retired Engineer
The basic problem is two things being multiplied together meaning the basic derivative property to use is the product rule:
(u•v)' = u'v + uv'
u = x2
u' (using the power rule) is 2x
v = (4x + 1)4
To find v' we must use both the power rule AND the chain rule so v' = 4(4x + 1)3•(4) (the "4" at the end is the derivative of the "4x + 1")
Put these together using (u•v)' = u'v + uv' = (2x)(4x + 1)4 + x2[4(4x + 1)3•(4)] and then simplify