## University Calculus: Early Transcendentals (3rd Edition)

(a) $\tan^{-1}{2}$ is defined. (b) $\cos^{-1}{2}$ is undefined
a) The domain of arctan includes all real numbers, so $\tan^{-1}{2}$ is defined. b) The domain of arccos lies between -1 and 1, but the value 2 does not lie in that interval, so $\cos^{-1}{2}$ is not defined.