Suppose that f and g are differentiable functions such that
Suppose that f and g are differentiable functions such that f(3)=4, g(3)=2, f\'(3)=-6, and g\'(3)=5.
Let h(x)=f(x) times g(x) and let k(x)=f(x)/f(x)-g(x).
a) calculate h\'(3)
b)calculate k\'(3)
Please show your work
Let h(x)=f(x) times g(x) and let k(x)=f(x)/f(x)-g(x).
a) calculate h\'(3)
b)calculate k\'(3)
Please show your work
Solution
Given
h(x)=f(x)g(x)
Then
h\'(x)=f(x)g\'(x)+f\'(x)g(x)
Thus
h\'(3)=f(3)g\'(3)+f\'(3)g(3)=4*5+(-6)(2)=20-12=8
k(x)=f(x)(f(x)-g(x))-1
Then
k\'(x)=f\'(x)(f(x)-g(x))-1+f(x)(-1)(f(x)-g(x))-2(f\'(x)-g\'(x))
Thus
k\'(3)=f\'(3)(f(3)-g(3))-1+f(3)(-1)(f(3)-g(3))-2(f\'(3)-g\'(3))
=-6((4-2)-1+4(-1)(4-2))-2(-6-(5))
=-3+2(11)=19
