Prove that \(Sin(90 – \theta)\) = \(Cos\theta\).
Solution : Draw a right angled triangle ABC right angled at B. Let \(\angle\) A = \(\theta\), then \(\angle\) C = 90 – \(\theta\) cos A = \(cos\theta\) = \(AB\over AC\) ……..(1) sin C = \(sin(90 – \theta)\) = \(AB\over AC\) …
Prove that \(Sin(90 – \theta)\) = \(Cos\theta\). Read More »