Question

If A = 60° and B = 30°, verify that : sin (A + B) = sin A cos B + cos A sin B

Prove that : tan θ/(1 − cot θ) + cot θ/(1 − tan θ) = 1 + sec θ cosec θ

In a right triangle ABC, right-angled at A, if sin B = 1/4, then the value of sec B is

An observer 1.8 m tall stands away from a chimney at a distance of 38.2 m along the ground. The angle of elevation of top of chimney from the eyes of observer is 45°. The height of chimney above the ground is