Answer
$-\frac{\sqrt 2}{2}$
Work Step by Step
Given: $-4arcsinx=\pi$
$arcsinx=-\frac{\pi}{4}$ (Divide by -4)
Apply definition of arcsine.
$x=sin(-\frac{\pi}{4})$
$x=-\frac{1}{\sqrt 2}$
Rationalize the denominator.
$x=-\frac{1}{\sqrt 2}\times=-\frac{\sqrt 2}{2}$
