Question

Prove that
sin 75-sin 15=cos 105+cos 15​

Answer 1

Answer:

 

Step-by-step explanation

RHS = cos 105° + cos 15°

         = cos (90° + 15°) + cos (90° – 75°)  

         = – sin 15° + sin 75°

         = sin 75° – sin 15°

          = LHS

Answer 2

Answer:

Step-by-step explanation:

sin75-sin15

=sin (90-15)-(-cos (90+15))

=cos 15+cos 105