a) let y = f(x) * g(x)
then y' = f(x)* g '(x) + g(x) * f '(x)
given:
f(4) = 3
f '(4) = -2
g(4) = 6
g '(4) = -4
so
y' = 3(-4) + 6(-2) = -24
how did you get -27 ?
do the others the same way
Suppose f(x) and g(x) are functions of x differentiable at x = 4. Given that f(4) = 3, f'(4) = -2, g(4) = 6, g'(4) = -4, find the value of each of the following.
a. Derivative of f(x) * g(x)
My answer: -27
b. Derivative of (f(x))/(g(x))
My answer: 1/12
c. Derivative of (g(x))/(f(x))
My answer: -1/3
d. A tangent line to f(x) at x = 4.
My answer: -2x + 11 (not sure)
2 answers
I'm sorry, g'(x) = -5.
1 answer