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Question
Prove the following
sin θ sin (90° − θ) − cos θ cos (90° − θ) = 0
Solution
We have to prove sin θ sin (90° − θ) − cos θ cos (90° − θ) = 0
Left-hand side
`= sin theta.sin(90^@ - theta) - cos theta.cos(90^@ - theta)`
`= sin theta.cos theta - cos thete.sin theta`
`= sin theta (cos theta -cos theta)`
= 0
=Right hand side
Proved
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