Check sibling questions

Ex 8.4, 5 (v) - Chapter 8 Class 10 Introduction to Trignometry (Term 1)

Last updated at Aug. 11, 2021 by

Ex 8.4, 5 - Chapter 8 Class 10 Introduction to Trignometry - Part 10

Ex 8.4, 5 - Chapter 8 Class 10 Introduction to Trignometry - Part 11

This video is only available for Teachoo black users

Subscribe Now

Introducing your new favourite teacher - Teachoo Black, at only ₹83 per month

Join Teachoo Black

Transcript

Ex 8.4, 5 Prove the following identities, where the angles involved are acute angles for which the expressions are defined. "cos A sin A + 1" /"cos A + sin A 1" = cosec A + cot A, using the identity cosec2 A = 1 + cot2 A. Taking L.H.S (cos sin + 1)/(cos + sin 1) divide both numerator and denominator by sin A = (1/sin (cos sin + 1 ))/(1/sin (cos + sin 1 ) ) = (cos /sin sin /sin + 1/sin )/(cos /sin + sin /sin 1/sin ) = cot 1 + /cot + 1 = ((cot + ) 1 )/((cot + 1 ) ) = ((co + ) ( 2 2 ) )/((cot + 1 )) = ((co + ) (cot )(cot + ) )/((cot + 1 )) = ((co + ) [1 ( )] )/([cot + 1 ]) = ((co + ) [1 + ] )/([cot + 1 ]) = cot A + cosec A = R.H.S Hence proved

Davneet Singh's photo - Teacher, Engineer, Marketer

Made by

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.