NCERT Exemplar Solutions
Class 11 - Mathematics - Chapter 3: TRIGONOMETRIC FUNCTIONS
True or False

In each of the Exercises 68 to 75, state whether the statements is True or False? Also give justification.

Quick Links to Questions

Question. 68

If \( \, \tan A = \dfrac{1 - \cos B}{\sin B} \, \) then \( \, \tan 2A = \tan B \, \).

Answer:

True

Question. 69

The equality \( \, \sin A + \sin 2A + \sin 3A = 3 \, \) holds for some real value of \(A\).

Answer:

False

Question. 70

\( \, \sin 10^\circ \, \) is greater than \( \, \cos 10^\circ \, \).

Answer:

False

Question. 71

\( \cos \dfrac{2\pi}{15} \, \cos \dfrac{4\pi}{15} \, \cos \dfrac{8\pi}{15} \, \cos \dfrac{16\pi}{15} = \dfrac{1}{16} \).

Answer:

True

Question. 72

One value of \(\theta\) which satisfies the equation \( \, \sin^4 \theta - 2 \sin^2 \theta - 1 \, \) lies between \(0\) and \(2\pi\).

Answer:

False

Question. 73

If \( \, \csc x = 1 + \cot x \, \) then \( x = 2n\pi \) or \( x = 2n\pi + \dfrac{\pi}{2} \).

Answer:

True

Question. 74

If \( \, \tan \theta + \tan 2\theta + \sqrt{3} \, \tan \theta \, \tan 2\theta = \sqrt{3} \, \), then \( \, \theta = \dfrac{n\pi}{3} + \dfrac{\pi}{9} \, \).

Answer:

True

Question. 75

If \( \, \tan(\pi \cos \theta) = \cot(\pi \sin \theta) \, \) then \( \, \theta - \dfrac{\pi}{4} = \pm \dfrac{1}{2\sqrt{2}} \, \).

Answer:

True

NCERT Exemplar Solutions Class 11 – Mathematics – Chapter 3: TRIGONOMETRIC FUNCTIONS – True or False | Detailed Answers