Question

maths 2nd sum 1 st bit

Answer 1

$\sin( \alpha + \beta ) = \sin( \alpha ) \cos( \beta ) + \sin( \beta ) \cos( \alpha ) \\ \sin(2a) = \sin(a) \cos(a) + \sin(a) \cos(a) \\ \sin(2a) = 2\sin(a) \cos(a)$
$\sin(2a) = 2 \sin(a) \cos(a) \\ \sin(2a) = (2 \sin(a) \cos(a) )( \frac{ \cos(a) }{ \cos(a) } ) \\ \sin(2a) = 2( \frac{ \sin(a) }{ \cos(a) } )( { \cos(a) }^{2} ) \\ \sin(2a) = 2 \frac{ \tan(a) }{ { \sec(a) }^{2} } \\ \sin(2a) = \frac{ 2\tan(a) }{1 + { \tan(a) }^{2} }$