## Calculus: Early Transcendentals 8th Edition

When $-2\leq x\leq-1, y=-2x-2$ When $-1\lt x\leq1, y=\sqrt{1-x^2}$
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 $-1\lt x\leq1,$ $x^2+y^2=1, y\geq0$ $y=\sqrt{1-x^2}$