Question

How do you evaluate `sin(45)cos(15)+cos(45)sin(15)`?

Answer 1

`:. sin 45 cos 15 + cos 45 sin 15 = sin (45 + 15) = sin 60 = sqrt 3/2`

Explanation:

`sin 45 cos 15 + cos 45 sin 15`

It is in the form `sin a cos b + cos a sin b`

But we know `sin (a + b) = sin a cos b + cos a sin b`

`:. sin 45 cos 15 + cos 45 sin 15 = sin (45 + 15) = sin 60 = sqrt 3/2`