# What is the domain and range of y=x^2+3?

Sep 7, 2015

Domain is $\mathbb{R}$

Range is <3;+oo)

#### Explanation:

Domain of a function is a subset of $\mathbb{R}$ where function value can be calculated. In this example there are no limitations for $x$. They would appear if there was for example a square root or if $x$ was in the denominator.

To calculate the range you have to analyse the graph of a function:

graph{(y-x^2-3)(x^2+(y-3)^2-0.04)=0 [-8.6, 9.18, -0.804, 8.08]}

From this graph you can easily see, that the function takes all values greater han or equal to $3$.