## Precalculus (6th Edition) Blitzer

$2$
Solve. $1+\sin^2 40^{\circ}+\sin^2 50^{\circ}$ We have $= 1+\sin^2 (90^{\circ}-50^{\circ})+\sin^2 50^{\circ}$ or, $=1+\cos^2 50^{\circ}+\sin^2 50^{\circ}$ or, $=1+1$ or, $=2$