Question

PROVE :

sin^2(-300°).cos^2 (120)+ cos^2(-240 ).sin^2(390)=1/4​

Answer 1

Explanation:

`\sin {}^(2) ( - 300) \cos {}^(2) (120) + \cos {}^(2) ( - 240) \sin {}^(2) (390) = (1)/(4)`

`\sin {}^(2) (60) \cos {}^(2) ( {}^{} 120) + \cos {}^(2) (120) \sin {}^(2) (30)`

`(3)/(4) (1)/(4) + (1)/(4) (1)/(4)`

`(3)/(16) + (1)/(16) = (4)/(16) = (1)/(4)`