We know 1+cot2A=cosec2A
⇒1+cot2A=1sin2A⇒sin2A=11+cot2A⇒sinA=√11+cot2A⇒sinA=1√1+cot2A
Express the trigonometric ratios sin A , sec A and tan A in terms of cot A
Write all the other trigonometric ratios of ∠A in terms of sec A.