Finding Value of trignometric functions, given angle
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
Ex 3.2, 10 Important
Example 9 Important
Ex 3.2, 6
Ex 3.2, 7 Important
Example 10
Ex 3.3, 1 Important You are here
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
Finding Value of trignometric functions, given angle
Last updated at April 16, 2024 by Teachoo
Ex 3.3, 1 Prove that sin2 π/6 + cos2 π/3 – tan2 π/4 = – 1/2 Solving L.H.S sin2 π/6 + cos2 π/3 − tan2 π/4 Putting π = 180° = sin2 (180° )/6 + cos2 (180° )/3 – tan2 (180° )/6 = sin2 30° + cos2 60° – tan2 45° Putting sin 30° = 1/2 , sin 60° = 1/2 , tan 45° = 1 = (𝟏/𝟐)^𝟐 + (𝟏/𝟐)^𝟐 – 12 = 1/4+ 1/4 −1 = (1 + 1 − 4 )/4 = (−2)/4 = (−𝟏)/𝟐 = R.H.S. Hence proved