# How do you find the domain of x^2 + 4?

Jun 29, 2017

See below.

#### Explanation:

The domain is the values that $x$ can take on, without causing $y$ to be indeterminant.

As $x$ approaches $\infty$, ${x}^{2} + 4$ approaches $\infty$.

As $x$ approaches $- \infty$, ${x}^{2} + 4$ approaches $\infty$.

As $x$ approaches $0$, ${x}^{2} + 4$ approaches $4$.

This is actually the graph of a quadratic (where $x$ can take on any value), so the domain is $\left(- \infty , \infty\right)$.