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Last updated at May 29, 2018 by Teachoo

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Ex 8.4, 1 Express the trigonometric ratios sin A, sec A and tan A in terms of cot A. tan A We know that tan A = ๐/๐๐๐โก๐จ cosec A We know that 1 + cot2 A = cosec2 A cosec2 A = 1 + cot2 A cosec A = ยฑ โ(1+๐๐๐ก2 ๐ด) Here, A is acute (i.e. less than 90ยฐ) & cosec A is positive when A is acute So, cosec A = โ(1+๐๐๐ก2 ๐ด) sin A sin A = ๐/(๐๐๐๐๐ ๐จ) Putting value of cosec A found above sin A = 1/(โ(1 + ๐๐๐ก2 ๐ด) ) Sec A We know that 1 + tan2 A = sec2 A sec2 A = 1 + tan2 A sec A = ยฑ โ((1+๐ก๐๐2 ๐ด)) Here, A is acute (i.e. less than 90ยฐ) & sec A is positive when A is acute sec A = โ((1+๐ก๐๐2 ๐ด)) sec A = โ((1+1/(๐๐๐ก2 ๐ด))) sec A = โ(((๐๐๐ก2 ๐ด + 1)/(๐๐๐ก2 ๐ด)) ) sec A = โ(๐๐๐ก2 ๐ด + 1)/cotโก๐ด

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Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.