Question

$if \: cos \frac{ \alpha }{3} = \frac{1}{2} \: find \: the \: value \: of \: sin \alpha .$

Answer 1

$heya \\ \\ \\ \cos( \alpha \div 3) = \cos(60) \\ \\ \\ becoz \: \cos(60) = 1 \div 2 \\ \\ \\ \\ = > \\ \\ \\ \alpha \div 3 = 60 \\ \\ \\ \alpha = 180 \\ \\ \\ so \: \: sin( \alpha ) = \sin(180) = 0 \\ \\ becoz \: sin( 180 ) = 0$

Answer 2

here sin 90-tita equals to cos tita