Give me the best solution of ncert class 10 of chapter introduction of trigonometry . How i solve the tricky question of exercise 8.4 question no. 2. Find the best and easiest way to solve the trigonometry question with trick. Write all the other trigonometric ratios of ∠A in terms of sec A.

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Cos A function in terms of sec A:

sec A = 1/cos A

⇒ cos A = 1/sec A

sec A function in terms of sec A:

cos

^{2}A + sin^{2}A = 1Rearrange the terms

sin

^{2}A = 1 – cos^{2}Asin

^{2}A = 1 – (1/sec^{2}A)sin

^{2}A = (sec^{2}A-1)/sec^{2}Asin A = ± √(sec

^{2}A-1)/sec Acosec A function in terms of sec A:

sin A = 1/cosec A

⇒cosec A = 1/sin A

cosec A = ± sec A/√(sec

^{2}A-1)Now, tan A function in terms of sec A:

sec

^{2}A – tan^{2}A = 1Rearrange the terms

⇒ tan

^{2}A = sec^{2}A – 1tan A = √(sec

^{2}A – 1)cot A function in terms of sec A:

tan A = 1/cot A

⇒ cot A = 1/tan A

cot A = ±1/√(sec

^{2}A – 1)