# Thread: How do I find these derivatives?

1. ## How do I find these derivatives?

Suppose f and g are differentiable functions with the values shown in the table below. For each of the following functions h, find h '(4).

x = 4
f(x) = 2
g(x) = 5
f'(x) = 3
g'(x) = -2

(a) h(x) = f(x) + g(x)

h'(4)= __________

(b) h(x) = f(x) g(x)

h'(4)= __________

(c) h(x) = f(x) / g(x)

h'(4)= __________

Thank you!

2. Hey,

You are just solving the derivatives like normal but it is written in a strange way that may seem confusing at the first time.

For a) for instance, imagine f(x) to be x^2 and g(x) to be x

therefore h(x) = x^2 + x right? when you take the derivative of h(x) you take the derivative of each term.... so in my made up example h'(x) = 2x + 1 right?

The examples given are exactly the same. h(x) = f(x) + g(x) so..........
h'(x) = f'(x) + g'(x)

After that you can finally use the information given;
h'(4) = f'(4) + g'(4), and from the table you know those two values, so
h'(4) = 3 + (-2) = 1

Simply follow these steps and basic derivative steps to solve b) and c)

3. OOH silly me hahah. The wording of the problem confused me. Thank you very much =)