Question

Find the first derivative with respect to x of the following function: f(x)=(7x+3)(4-3x)

Answer 1

19 - 42x

Explanation:

To differentiate this, we must use the product rule
f'(x) = (7x+3)'(4-3x) + (4-3x)'(7x+3)
= (7)(4-3x) + (-3)(7x+3)
= 28 - 21x - 21x - 9
= 19 - 42x