Question

Find f(x) = 3x and g(x) = 1+3x, find f(4+h) and g(4+h) and f'(4) and g'(4). 

Answer 1

The functions are f(x) = 3x and g(x) = 1 + 3x

f(x) = 3x

f(4 + h) = 3(4 + h)

= 12 + 3h

f(4 + h) = 3h + 12

f(x) = 3x

Apply derivative on each side with respect of x.

f '(x) = 3

f '(4) = 3

g(x) = 1 + 3x

g(4 + h) = 1 + 3(4 + h)

= 1 + 12 + 3h

= 3h + 13

g(4 + h) = 3h + 13

g(x) = 1 + 3x

Apply derivative on each side with respect of x.

g '(x) = 3

g '(4) = 3.