## Precalculus (6th Edition) Blitzer

The domain of the function $f\left( x \right)={{x}^{2}}+6x-3$ is $f=\left( -\infty,\infty \right)$.
Consider the given function $f\left( x \right)={{x}^{2}}+6x-3$. We can see that this function contains neither division nor the square root. Also, the expression ${{x}^{2}}+6x-3$ represents a real number, for every value of $x$. Therefore, the domain of the given function is the set of all real numbers. Therefore, the domain of the function $f\left( x \right)={{x}^{2}}+6x-3$ is $f=\left( -\infty,\infty \right)$.