if g(x) = f(x)sinx, then
g'(x) = f(x)cosx + f'(x)sinx
g'(π/4) = f(π/4)cos(π/4) + f'(π/4)sin(π/4)
= -4(√2/2) + 7(√2/2) , since sinπ/4 = cosπ/4
= 3√2/2
repeat the same steps for h'(π/4)
Suppose that f(π4)=−4 and f′(π4)=7, and let g(x)=f(x)sinx and h(x)=cosxf(x). Answer the following questions.
1. Find g′(π/4).
2. Find h′(π/4).
1 answer