Calculus: Early Transcendentals (2nd Edition)

Domain: ${- \infty \leq x \leq \infty}$ Range: ${0 \leq y \leq \infty}$
Because $b^x$ is defined for all real numbers, the domain of $f$ is $x:{- \infty \leq x \leq \infty}$ Because $b^x \gt 0$ for all values of $x$, the range of $f$ is $y:{0 \leq y \leq \infty}$.