In This Post we are providing Chapter- 2 TRIGNOMETRIC FUNCTIONS NCERT MOST IMPORTANT QUESTIONS for Class 11 MATHS which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.
NCERT MOST IMPORTANT QUESTIONS ON TRIGNOMETRIC FUNCTIONS
1.Convert into radian measures. -370 30’
Ans. – 370 30’ = –
2.Prove Sin (n+1) x Sin (n+2) x + Cos (n+1) x. Cos (n+2) x = Cos x
Ans.L.H.S = Cos (n+1) x Cos (n+2) x + Sin (n+1) x Sin (n+2) x
=Cos 
=Cos x
3.Find the value of Sin
Ans. Sin 
= Sin 
= sin 
= Sin 
=
4.Find the principal solution of the eq. tan x =
Ans. tan x = 
5.Convert into radian measures.
Ans. 50 371 3011 = 50 + 
6.Evaluate 2 Sin
Ans.2 Sin 
6.Find the solution of Sin x =
Ans.Sin x = 
7.Prove that
Ans.L. H. S = tan 360
8.Find the value of tan
Ans.
9.Prove Cos 4x = 1 – 8 Sin2 x. Cos2x
Ans. L. H. S = Cos 4x
10.Find the value of Cos (- 17100).
Ans. Cos (-17100) = Cos (1800-90)[Cos (-θ) = Cos θ
= Cos [5 
360 +90]
= Cos 
= 0
11.A wheel makes 360 revolutions in 1 minute. Through how many radians does it turn in 1 second.
Ans.N. of revolutions made in 60 sec. = 360
N. of revolutions made in 1 sec = 
Angle moved in 6 revolutions = 2 π 6 = 12 π
12.If in two circles, arcs of the same length subtend angles 600 and 750 at the centre find the ratio of their radii.
Ans.
(1)
÷ ( 2)
13.Prove that Cos 6x= 32 Cos6x – 48 Cos4 x + 18 Cos2 x-1
Ans.L.H.S. = Cos 6x
= 
14.Solve Sin2x-Sin4x+Sin6x=o
Ans.
15.Prove that (Cos x + Cos y)2 + (Sin x – Sin y)2 = 4 Cos2
Ans. L. H. S = (Cos x + Cos y)2 + (Sin x – Sin y)2
