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Ex 8.4, 2 - Write all trigonometric ratios in terms of sec A - Ex 8.4

Ex 8.4, 2 - Chapter 8 Class 10 Introduction to Trignometry - Part 2
Ex 8.4, 2 - Chapter 8 Class 10 Introduction to Trignometry - Part 3

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Ex 8.4, 2 Write all the other trigonometric ratios of A in terms of sec A. cos A We know that cos A = / tan A We know that 1 + tan2 A = sec2 A tan2 A = sec2 A 1 tan A = ( 2 1) Here, A is acute (i.e. less than 90 ) & tan A is positive when A is acute tan A = ( 2 1) cot cot A = /( ) Putting value of tan A found above cot A = 1/( (sec^2 1 ) ) cosec A We know that 1 + cot2 A = cosec2 A cosec2 A = 1 + cot2 A cosec2 A = 1 + (1/( (sec^2 1 ) ))^2 cosec2 A = 1 + (1/( 2 1)) cosec2 A = ((1 ( 2 1) + 1)/( 2 1)) cosec2 A = (( 2 1 + 1)/( 2 1)) cosec2 A = ( 2 )/( 2 1) cosec A = (( 2 )/( 2 1)) cosec A = sec / ( 2 1 ) Here, A is acute (i.e. less than 90 ) & cosec A is positive when A is acute cosec A = sec / ( 2 1 ) sin A We know that sin A = /( ) sin A = 1/((sec / (sec^2 1 )) ) sin A = ( 2 1)/sec

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.