1. ## wierd derivative question

If
f(4) = 8, g(4) = 2, f(4) = 1, g(4) = 3, f '(4) = 10, g '(4) = 12, f '(4) = 6, and g '(4) = 2, find H '(4) where H(x) = g( f(x) 3x ) .

2. Originally Posted by kwivo
If
f(4) = 8, g(4) = 2, f(4) = 1, g(4) = 3, f '(4) = 10, g '(4) = 12, f '(4) = 6, and g '(4) = 2, find H '(4) where H(x) = g( f(x) 3x ) .
By the Chain Rule:

$H(x) = g(f(x) - 3x)$

$\Rightarrow H'(x) = g'(f(x) - 3x) \cdot (f'(x) - 3)$

now just plug in numbers, and you're done