Check sibling questions

Ex 8.3, 4 (iv) - Chapter 8 Class 10 Introduction to Trignometry

Last updated at Aug. 16, 2023 by

Slide24.JPG

Slide25.JPG

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class

Book a free demo

Transcript

Ex 8.3, 4 Prove the following identities, where the angles involved are acute angles for which the expressions are defined. ("1 + sec" A)/"sec A" ="sin2 A" /"1 – cos A" "[Hint : Simplify LHS and RHS separately]" (1 + sec⁡𝐴)/sec⁡〖 𝐴〗 = 1/sec⁡〖 𝐴〗 +sec⁡〖 𝐴〗/sec⁡〖 𝐴〗 = 1/sec⁡〖 𝐴〗 +1 = cos A + 1 (𝒔𝒊𝒏𝟐 𝑨)/(1 − cos⁡𝐴 ) = (𝟏 − 𝒄𝒐𝒔𝟐 𝑨)/(1 − cos⁡𝐴 ) = (12 − 𝑐𝑜𝑠2 𝐴)/(1 − cos⁡𝐴 ) = ((1 − 𝑐𝑜𝑠 𝐴)(1+ cos⁡〖𝐴)〗)/(1 − cos⁡𝐴 ) = 1 + cos A ∴ L.H.S = R.H.S Hence proved

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.