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Last updated at May 29, 2018 by Teachoo

Transcript

E ample, 10 Prove that 3sin /6 sec /3 4 sin 5 /6 cot /4 = 1 Taking L.H.S. 3sin /6 sec /3 - 4 sin 5 /6 cot /4 Putting = 180 = 3sin 180/6 sec 180/3 4 sin (5 180" " )/6 cot 180/4 = 3sin 30 sec 60 4 sin 150 cot 45 Solving, 3 sin 30 sec 60 - 4sin 150 cot 45 Putting the value = 3 1/2 2 - 4 1/2 1 = 3 2 = 1 = R.H.S. Hence proved

Finding Value of trignometric functions, given angle

Negative Angle Identities

Value of sin, cos, tan repeats after 2π

Shifting angle by π/2, π, 3π/2 , 2π

Example 8

Ex 3.2, 9 Important

Ex 3.2, 8 Important

Ex 3.2, 10 Important

Example 9 Important

Ex 3.2, 6

Ex 3.2, 7 Important

Example 10 You are here

Ex 3.3, 1

Ex 3.3, 2 Important

Ex 3.3, 3 Important

Ex 3.3, 4

Ex 3.3, 8 Important

Ex 3.3, 9 Important

Find values of sin 18, cos 18, cos 36, sin 36, sin 54, cos 54 Important

Chapter 3 Class 11 Trigonometric Functions

Concept wise

- Radian measure - Conversion
- Arc length
- Finding Value of trignometric functions, given other functions
- Finding Value of trignometric functions, given angle
- (x + y) formula
- 2x 3x formula - Proving
- 2x 3x formula - Finding value
- cos x + cos y formula
- 2 sin x sin y formula
- Finding Principal solutions
- Finding General Solutions
- Sine and Cosine Formula

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.