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Example 4 - Chapter 8 Class 10 Introduction to Trignometry (Term 1)
Last updated at May 29, 2018 by Teachoo
Examples
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Example 2 Important
Example 3
Example 4 You are here
Example 5 Important
Example 6
Example 7 Important
Example 8 Important
Example 9 Deleted for CBSE Board 2023 Exams
Example 10 Important Deleted for CBSE Board 2023 Exams
Example 11 Important Deleted for CBSE Board 2023 Exams
Example 12
Example 13 Important
Example 14 Important
Example 15 Important
Chapter 8 Class 10 Introduction to Trignometry
Serial order wise
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 = √2𝑘2 AC = k √2 We have to find 2 sin A cos A Substituting the value of sin A and cos A = 2 ×1/√2×1/√2 = 2/(√2 × √2) = 2/(√2 )^2 = 2/2 = 1
