## Calculus (3rd Edition)

(a) $x=3\sin \theta$. (b) $x=4\sec \theta$. (c) $x=4\tan \theta$. (d) $x=\sqrt 5 \sec \theta$.
The required substitution choices are as follows: (a) $x=3\sin \theta$. (b) $x=4\sec \theta$. (c) $x=4\tan \theta$. (d) $x=\sqrt 5 \sec \theta$.