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Last updated at May 29, 2018 by Teachoo

Transcript

Example 4 In a right triangle ABC, right-angled at B, if tan A = 1, then verify that 2 sin A cos A = 1. Finding AC by pythagoras theorem (Hypotenuse)2 = (Height)2 + (Base)2 AC2 = AB2 + BC2 Putting AB = BC = k AC2 = k2 + k2 AC2 = 2k2 AC = โ2๐2 AC = k โ2 We have to find 2 sin A cos A Substituting the value of sin A and cos A = 2 ร1/โ2ร1/โ2 = 2/(โ2 ร โ2) = 2/(โ2 )^2 = 2/2 = 1

Chapter 8 Class 10 Introduction to Trignometry

Concept wise

- Finding sin cos tan
- Finding sin cos when sides of a triangle are given
- Finding ratios when other ratios are given
- Finding values of expressions
- Proving
- Trignometric ratios of Specific Angles - Evaluating
- Trignometric ratios of complementry angles
- Expressing ratios in other ratios
- Evaluating using Trignometric Identities

About the Author

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.