sin(270 degrees - theta) = -cos(theta)

Answer 1

Prove the following identity:
sin(270 degrees - theta) = -cos(theta)

sin(270 degrees - theta)
= sin(270°)cos(θ) - cos(270°)sin(θ)
=(-1)cos(θ) - (0)sin(θ)
= -cos(θ)

Please post the complete question. It was not clear whether it was an equation to be solved or the proof of an identity required.

Answer 2

*verify that it is an identity

Answer 3

That's what I thought. Thank you for posting a complete question.