Change tan A to sin A/cos A and cot A to cos A/ sin A for easier manipulation.
Find common denominators and simplify the fractions.
Use the trigonometric identity and change cos2x + sin2x = 1.
Prove Trigonometric Identities involving Cotangent and Tangent . Additional Math Tuition. Woodlands, Choa Chu Kang, Yew Tee, Sembawang and Johor Bahru.