Last updated at June 29, 2018 by Teachoo

Transcript

Example 1 Given tan A = 4/3 , find the other trigonometric ratios of the angle A Given, tan A = 4/3 (๐ ๐๐๐ ๐๐๐๐๐ ๐๐ก๐ ๐ก๐ ๐๐๐๐๐ ๐ด)/(๐ ๐๐๐ ๐๐๐๐๐๐๐๐ก ๐ก๐ ๐๐๐๐๐ ๐ด) = 4/3 ๐ต๐ถ/๐ด๐ต = 4/3 Let BC = 4x AB = 3x We find AC using Pythagoras Theorem In right triangle ABC Using Pythagoras theorem (Hypotenuse)2 = (Height)2 + (Base)2 (AC)2 = (BC)2 + (AB)2 (AC)2 = (4x)2 + (3x)2 (AC)2 = 16x2 + 9x2 (AC)2 = 25x2 AC = โ25๐ฅ2 AC = 5x Now, sin A = (๐ ๐๐๐ ๐๐๐๐๐ ๐๐ก๐ ๐ก๐ ๐๐๐๐๐ ๐ด)/๐ป๐ฆ๐๐๐ก๐๐๐ข๐ ๐ sin A = ๐ต๐ถ/๐ด๐ถ sin A = 4๐ฅ/5๐ฅ Sin A = 4/5 Similarly, cos A = (๐ ๐๐๐ ๐๐๐๐๐๐๐๐ก ๐ก๐ ๐ด)/๐ป๐ฆ๐๐๐ก๐๐๐ข๐ ๐ cos A = ๐ด๐ต/๐ด๐ถ cos A = 3๐ฅ/5๐ฅ cos A = 3/5 Given, tan A=4/3

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.