Simplify sin 24 degrees cos 66 degrees sin 66 degrees cos

Simplify:

sin (24 degrees) * cos (66 degrees) + sin (66 degrees) cos (24 degrees)

Solution

sin 24 degrees cos 66 degrees + sin 66 degrees cos 24 degrees

This expression is of the form

sin A cos B + cos A sin B

which is equal to sin(A+B)

therefore the given expression can be written as sin(24+66) = sin 90=1