Question

sin θsin( 900– θ) – cos θcos( 900– θ) = ?

Answer 1

Step-by-step explanation:

solution:let us theta= X,y sinxsin(900-0)-cosxcos(900-0)

=sin xcos y - cos x sin y

=sin(x - y) .

I hope you understand.

Answer 2

Answer:

Step-by-step explanation:

sinxsin(720+180-x)-cosxcos(720+180-x) (sin(2pi+x)=sinx)

sinxsin(180-x)-cosxcos(180-x)

sinxsinx+cosxcosx

cos(x-x)=1