Question 1 (i) - sin 90 - θ, cos 90 - θ formula - Chapter 8 Class 10 Introduction to Trignometry

Last updated at August 17, 2026 by

Ex 8.3, 1 - Evaluate (i) sin 18 / cos 72 (ii) tan 26/cot 64 - Trignometric ratios of complementry angles

 

 

Remove Ads Take short quiz All Quiz and Worksheets
Teachoo · Class 10 Explore Class 10

Transcript

Question 1 Evaluate : (i) sin 18 /cos 72 sin 18 /cos 72 = sin 18 /cos (90 18 ) = sin 18 /(sin 18 ) = 1

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh is an IIT Kanpur graduate and has been teaching for 16+ years. At Teachoo, he breaks down Maths, Science and Computer Science into simple steps so students understand concepts deeply and score with confidence.

Many students prefer Teachoo Black for a smooth, ad-free learning experience.