# What is the second derivative of #f(x)=e^x + e^(-x / 2 #?

##### 2 Answers

the first derivative by using the chain rule is

then take the derivative of that function

therefore,

again using the chain rule on the second element,

therefore the answer is

=

#### Explanation:

Since the second derivative is the derivative of the first derivative, we start by finding:

Re-writing:

We know

We need to use the Chain Rule for

We now differentiate this again:

Re-writing as before: