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Last updated at Aug. 11, 2021 by Teachoo

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

Ex 8.4

Ex 8.4, 1

Ex 8.4, 2 Important

Ex 8.4, 3 (i) Important

Ex 8.4, 3 (ii)

Ex 8.4, 4 (i) [MCQ]

Ex 8.4, 4 (ii) [MCQ] Important

Ex 8.4, 4 (iii) [MCQ] Important

Ex 8.4, 4 (iv) [MCQ]

Ex 8.4, 5 (i) Important

Ex 8.4, 5 (ii)

Ex 8.4, 5 (iii) Important

Ex 8.4, 5 (iv) Important

Ex 8.4, 5 (v) Important You are here

Ex 8.4, 5 (vi)

Ex 8.4, 5 (vii) Important

Ex 8.4, 5 (viii)

Ex 8.4, 5 (ix) Important

Ex 8.4, 5 (x)

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.