Answer
When $-2\leq x\leq-1, y=-2x-2$
When $-1\lt x\leq1, y=\sqrt{1-x^2}$
Work Step by Step
For $-2\leq x\leq-1,$
$y-y_1=\frac{y_2-y_1}{x_2-x_1}(x-x_1)$
$y-2=\frac{0-2}{-1-(-2)}(x-(-2))$
$y=-2x-2$
For $-1\lt x\leq1,$
$x^2+y^2=1, y\geq0$
$y=\sqrt{1-x^2}$
