Find the Domain and Range y=cos(pi/4)

The domain of the expression is all real numbers except where the expression is undefined. In this case, there is no real number that makes the expression undefined.

${\displaystyle y=\frac{\sqrt{2}}{2}}$ is a straight line perpendicular to the ${\displaystyle y}$-axis, which means that the range is a set of one value ${\displaystyle \left\{y\right|y=\frac{\sqrt{2}}{2}\}}$.

Set-Builder Notation:

Determine the domain and range.

Domain: ${\displaystyle (-\infty ,\infty ),\left\{x\right|x\in ℝ\}}$

Range: ${\displaystyle \left\{y\right|y=\frac{\sqrt{2}}{2}\}}$