If f(6) = 7, g(6) = 5, f '(6) = -2, and g'(6) = 8, find the following numbers.

Question

(a) (f + g)'(6)

(b) (fg)'(6)

How do you go about approaching these kinds of problems? Thanks

Answer 1

In a) you use that:

(f+g)'(x) = f'(x) + g'(x)

In b) you use that:

(f*g)' = fg' + f'g