Last updated at Dec. 8, 2016 by Teachoo

Transcript

Example 6 If cos𝑥 = – 3/5 , x lies in third quadrant, find the values of other five trigonometric functions. Since x is in lllrd Quadrant sin and cos will be negative But tan will be positive Given cos x = (−3)/5 We know that sin2 x + cos2 x = 1 sin2 x + ((−3)/5)^2 = 1 sin2 x + 9/25 = 1 sin2 x = 1 – 9/25 sin2 x = (25 − 9)/25 sin2x = 16/25 sin x = ±√(16/25) sin x = ± 4/5 Since, x is in lllrd Quadrant sin x is negative lllrd Quadrant ∴ sin x = −4/5 tan x = sin𝑥/cos𝑥 = (− 4/5)/(− 3/5) = (−4)/5 × 5/(−3) = 4/3 cosec x = 1/sin𝑥 = 1/(− 4/5) = (−5)/4 sec x = 1/cos𝑥 = 1/((−3)/5) = 5/(−3) = (−5)/3 cot x = 1/tan𝑥 = 1/(4/3) = 3/4

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6 You are here

Example 7

Example 8

Example 9

Example 10

Example 11

Example 12

Example 13

Example 14

Example 15

Example 16

Example 17

Example 18

Example 19

Example 20

Example 21

Example 22

Example 23

Example 24 Important

Example 25

Example 26

Example 27 Important

Example 28 Important

Example 29

Chapter 3 Class 11 Trigonometric Functions

Serial order wise

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.