Answer
$\sqrt{1 – x^2}$
Work Step by Step
let, $\sin ^ {–1} x = \theta$
then, $\sin \theta = x$ – –––(1)
To evaluate
$\cos (\sin ^ {–1} x) = \cos \theta$
We know,
$\cos \theta = \sqrt{1 – \sin^{2} \theta}$
using(1)
$\cos \theta = \sqrt{1 – x^2}$