F(x) = {2}^(x) + 3 What is the value of f(-2)​

Question

`f(x) = {2}^(x) + 3`
What is the value of f(-2)​

Answer 1

The function is given
`f(x)=2^x+3`.

Now let's solve for
`f(-2)`.

`f(-2)=2^(-2)+3`

Rule of negative exponent:
`x^(-1)=(1)/(x^1)`.

`f(-2)=(1)/(2^2)+3`

`f(-2)=(1)/(4)+(3)/(1)`

Rule for sum of fractions:
`(a)/(b)+(c)/(d)=(ad+bc)/(bd)`.

`f(-2)=(13)/(4)`

And the result is:

`f(-2)=\boxed{(13)/(4)=3.25}`