Question

plz answer plz plz plz plz

Answer 1

$\sin( \alpha ) = \frac{12}{13} \\ \cos( \alpha ) = \sqrt{1 - \frac{144}{169} } \\ = + \frac{5}{13} \: or - \frac{5}{13} \\ \cos( \alpha ) = {cos}^{2} \frac{ \alpha }{2} - {sin}^{2} \frac{ \alpha }{2 } \\ = 1 - 2 {sin}^{2} \frac{ \alpha }{2} \\ \frac{5}{13} = 1 - 2 {sin}^{2} \frac{ \alpha }{2} \\ \frac{8}{13} = 2 {sin}^{2} \frac{ \alpha }{2} \\ sin \frac{ \alpha }{2} = \frac{2}{ \sqrt{13} }$

similarly find cos