Question

3" alt="f(x) = {2}^{x} + 3" align="absmiddle" class="latex-formula">
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: $x^{-1}=\frac{1}{x^1}$.

$f(-2)=\frac{1}{2^2}+3$

$f(-2)=\frac{1}{4}+\frac{3}{1}$

Rule for sum of fractions: $\frac{a}{b}+\frac{c}{d}=\frac{ad+bc}{bd}$.

$f(-2)=\frac{13}{4}$

And the result is:

$f(-2)=\boxed{\frac{13}{4}=3.25}$