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Ex 8.1, 6 - Chapter 8 Class 10 Introduction to Trignometry
Last updated at August 17, 2026 by Teachoo
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
Transcript
Ex 8.1, 6 If โ A and โ B are acute angles such that cos A = cos B, then show that โ A = โ B. cos A = (๐ ๐๐๐ ๐๐๐๐๐๐๐๐ก ๐ด)/๐ป๐ฆ๐๐๐ก๐๐๐ข๐ ๐ = ๐จ๐ช/๐จ๐ฉ Similarly, cos B = (๐ ๐๐๐ ๐๐๐๐๐๐๐๐ก ๐ต)/๐ป๐ฆ๐๐๐ก๐๐๐ข๐ ๐ = ๐ฉ๐ช/๐จ๐ฉ Now, given that cos A = cos B ๐ด๐ถ/๐ด๐ต = ๐ต๐ถ/๐ด๐ต AC = BC We know that in a triangle, angles opposite equal sides are equal โ B = โ ๐ Hence proved.
