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Ex 8.1, 3 - If sin A = 3/4, calculate cos A and tan A. - Ex 8.1

Ex 8.1, 3 - Chapter 8 Class 10 Introduction to Trignometry - Part 2
Ex 8.1, 3 - Chapter 8 Class 10 Introduction to Trignometry - Part 3

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Ex 8.1, 3 If sin A = 3/4 , calculate cos A and tan A. sin A = 3/4 (𝑠𝑖𝑑𝑒 𝑜𝑝𝑝𝑜𝑠𝑖𝑡𝑒 𝑡𝑜 ∠𝐴)/𝐻𝑦𝑝𝑜𝑡𝑒𝑛𝑢𝑠𝑒 = 3/4 ⇒ 𝐵𝐶/𝐴𝐶 = 3/4 Let BC = 3x AC = 4x We find AB using Pythagoras Theorem Hence, using Pythagoras theorem (Hypotenuse)2 = (Height)2 + (Base)2 AC2 = AB2 + BC2 (4x)2 = AB2 + (3x)2 16x2 = AB2 + 9x2 16x2 – 9x2 = AB2 7x2 = AB2 AB2 = 7x2 AB = √7𝑥2 AB = √7 x Now, we need to find cos A & tan A

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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.