Question

pls explain sin(x+1)-sinx=2cos(x+1/2 )sin(1/2)​

Answer 1

Answer:

We known sinC- sinD=2cos([C+D]/2)*sin([C-D]/2)

Sin(x+1)-sinx=2cos([x+1+x]/2) sin([x+1-x]/2)

=2cos((2x+1)/2)sin(1/2)

=2cos(2x/2+1/2)sin(1/2)

=2cos(x+1/2)sin(1/2)

Hence proved