Question

Упростите выражение
1) 3sin^2a-3; 2) 2-cos^2x/5-sin^2x/5

Answer 1

$1) \: \: \: \: 3 {(sin \alpha )}^{2} - 3 = 3 \times ( {(sin \alpha )}^{2} - 1) = - 3 {(cos \alpha )}^{2} \\ \\ 2) \: \: \: \: 2 - {(cos \frac{x}{5} )}^{2} - {(sin \frac{x}{5} )}^{2} = 2 - ({(cos \frac{x}{5} )}^{2} + {(sin \frac{x}{5} )}^{2} ) = 2 - 1 = 1$