Question

If sin 2a = 2 sin a
Then find a

Answer 1

Answer :

$\sin2( \alpha ) = 2 \sin( \alpha ) \\ 2 \sin( \alpha ) \cos( \alpha ) = 2 \sin( \alpha ) \\ \cos( \alpha ) = 1$

Then :

$\alpha = 0$

Answer 2

Answer:

As we know

sin2a= 2sina cosa

Now on putting this in the question

2sina cosa= 2sina

2sina cosa - 2sina= 0

2sina(cosa-1)=0

2sina=0 or cosa - 1 = 0

sina=0 or cosa=1

a=0°