Question

cos^2 x=0.5, найти 2sin^2a-1

35 балов

Answer 1

Ответ:

${ \cos}^{2} (\alpha ) = 1 - { \sin }^{2} ( \alpha )$

${ \sin}^{2} ( \alpha ) = 1 - { \cos}^{2} (\alpha ) = 1 - 0.5 = 0.5$

$2 { \sin}^{2} (\alpha ) - 1 = 2 \times 0.5 - 1 = 0$