Question

Question 4. Prove karein Cos 57° Sin 51° -Sin 33° Cos 39° = 0.​

Answer 1

we know that

cosA= sin(90-A)

sinA= cos(90-A)

therefore we can say that

cos57=sin(90-57)=sin 33

cos39=sin(90-39)=sin 51

so on substituting the values of cos57 and cos39 in question above we get

sin33 sin51 - sin33 sin51

=0