## Precalculus (6th Edition)

$\left( 2\sin x+1\right) \left( \sin x+1\right)$
$2\sin ^{2}x+3\sin x+1=\left( 2\sin x+1\right) \left( \sin x+1\right)$ (We need to choose factors of 2 and 1 ) and try to get correct result)