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Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class


Ex 8.3, 4 Prove the following identities, where the angles involved are acute angles for which the expressions are defined. ("1 + sec" A)/"sec A" ="sin2 A" /"1 โ€“ cos A" "[Hint : Simplify LHS and RHS separately]" (1 + secโก๐ด)/secโกใ€– ๐ดใ€— = 1/secโกใ€– ๐ดใ€— +secโกใ€– ๐ดใ€—/secโกใ€– ๐ดใ€— = 1/secโกใ€– ๐ดใ€— +1 = cos A + 1 (๐’”๐’Š๐’๐Ÿ ๐‘จ)/(1 โˆ’ cosโก๐ด ) = (๐Ÿ โˆ’ ๐’„๐’๐’”๐Ÿ ๐‘จ)/(1 โˆ’ cosโก๐ด ) = (12 โˆ’ ๐‘๐‘œ๐‘ 2 ๐ด)/(1 โˆ’ cosโก๐ด ) = ((1 โˆ’ ๐‘๐‘œ๐‘  ๐ด)(1+ cosโกใ€–๐ด)ใ€—)/(1 โˆ’ cosโก๐ด ) = 1 + cos A โˆด L.H.S = R.H.S Hence proved

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.