Example 9 - Chapter 8 Class 10 Introduction to Trignometry

Last updated at Dec. 13, 2024 by Teachoo

Example 9 - Express cos A, tan A and sec A in terms of sin A - Examples

part 2 - Example 9 - Examples - Serial order wise - Chapter 8 Class 10 Introduction to Trignometry

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Example 9 Express the ratios cos A, tan A and sec A in terms of sin A. cos A Since, cos2 A + sin2 A = 1 cos2 A = 1 – sin2 A cos A = ±√(𝟏 −𝒔𝒊𝒏𝟐 𝑨) Here, A is acute (i.e. less than 90°) & cos A is positive when A is acute So, cos A = √(𝟏 −𝒔𝒊𝒏𝟐 𝑨) sec A sec A = 1/cos⁡〖 𝐴〗 sec A = 𝟏/√(𝟏 −𝒔𝒊𝒏𝟐 𝑨) tan A We know that tan A = 𝑠𝑖𝑛⁡〖 𝐴〗/𝑐𝑜𝑠⁡〖 𝐴〗 Putting value of cos A tan A = 𝒔𝒊𝒏⁡〖 𝑨〗/√(𝟏 − 𝒔𝒊𝒏𝟐 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 14 years. He provides courses for Maths, Science and Computer Science at Teachoo

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