NCERT Exemplar Solutions
Class 12 - Mathematics - Chapter 2: INVERSE TRIGONOMETRIC FUNCTIONS
Objective Type Question

Choose the correct answer from the given four options:

Question.  20

Which of the following is the principal value branch of \(\cos^{-1} x\)?

(a)

\([-\dfrac{\pi}{2}, \dfrac{\pi}{2}]\)

(b)

(0, \pi)

(c)

[0, \pi]

(d)

(0, \dfrac{\pi}{2}]

Question.  21

Which of the following is the principal value branch of \(\csc^{-1} x\)?

(a)

\((-\dfrac{\pi}{2}, -\dfrac{\pi}{2})\)

(b)

[0, \pi] - \{\dfrac{\pi}{2}\}

(c)

\([-\dfrac{\pi}{2}, \dfrac{\pi}{2}]\)

(d)

\([-\dfrac{\pi}{2}, \dfrac{\pi}{2}] - \{0\}\)

Question.  22

If \(3 \tan^{-1} x + \cot^{-1} x = \pi\), then \(x\) equals

(a)

0

(b)

1

(c)

-1

(d)

\(\dfrac{1}{2}\)

Question.  23

The value of \(\sin^{-1}\left(\cos \dfrac{33\pi}{5}\right)\) is

(a)

\(\dfrac{3\pi}{5}\)

(b)

\(-\dfrac{7\pi}{5}\)

(c)

\(\dfrac{\pi}{10}\)

(d)

\(-\dfrac{\pi}{10}\)

Question.  24

The domain of the function \(\cos^{-1}(2x - 1)\) is

(a)

[0, 1]

(b)

[-1, 1]

(c)

(-1, 1)

(d)

[0, \pi]

Question.  25

The domain of the function defined by \(f(x) = \sin^{-1} \sqrt{x - 1}\) is

(a)

[1, 2]

(b)

[-1, 1]

(c)

[0, 1]

(d)

none of these

Question.  26

If \(\cos\left(\sin^{-1} \dfrac{2}{5} + \cos^{-1} x\right) = 0\), then \(x\) is equal to

(a)

\(\dfrac{1}{5}\)

(b)

\(\dfrac{2}{5}\)

(c)

0

(d)

1

Question.  27

The value of \(\sin(2 \tan^{-1}(0.75))\) is equal to

(a)

.75

(b)

1.5

(c)

.96

(d)

\(\sin^{-1} 5\)

Question.  28

The value of \(\cos^{-1}(\cos \dfrac{3\pi}{2})\) is equal to

(a)

\(\dfrac{\pi}{2}\)

(b)

\(3\pi\)

(c)

\(\dfrac{5\pi}{2}\)

(d)

\(7\pi\)

Question.  29

The value of the expression \(2 \sec^{-1} 2 + \sin^{-1} \left(\dfrac{1}{2}\right)\) is

(a)

\(\dfrac{\pi}{6}\)

(b)

\(\dfrac{5\pi}{6}\)

(c)

\(\dfrac{7\pi}{6}\)

(d)

1

Question.  30

If \(\tan^{-1} x + \tan^{-1} y = \dfrac{4\pi}{5}\), then \(\cot^{-1} x + \cot^{-1} y\) equals

(a)

\(\dfrac{\pi}{5}\)

(b)

\(\dfrac{2\pi}{5}\)

(c)

\(\dfrac{3\pi}{5}\)

(d)

\(\pi\)

Question.  31

If \(\sin^{-1}\left(\dfrac{2a}{1 + a^{2}}\right) + \cos^{-1}\left(\dfrac{1 - a^{2}}{1 + a^{2}}\right) = \tan^{-1}\left(\dfrac{2x}{1 - x^{2}}\right)\), where \(a, x \in (0, 1)\), then the value of \(x\) is

(a)

0

(b)

\(\dfrac{a}{2}\)

(c)

a

(d)

\(\dfrac{2a}{1 - a^{2}}\)

Question.  32

The value of \(\cot \left[ \cos^{-1} \left(\dfrac{7}{25}\right) \right]\) is

(a)

\(\dfrac{25}{24}\)

(b)

\(\dfrac{25}{7}\)

(c)

\(\dfrac{24}{25}\)

(d)

\(\dfrac{7}{24}\)

Question.  33

The value of the expression \(\tan\left(\dfrac{1}{2} \cos^{-1} \dfrac{2}{\sqrt{5}}\right)\) is

(a)

\(2 + \sqrt{5}\)

(b)

\(\sqrt{5} - 2\)

(c)

\(\dfrac{\sqrt{5} + 2}{2}\)

(d)

5 + \sqrt{2}

Question.  34

If \(x \le 1\), then \(2 \tan^{-1} x + \sin^{-1}\left(\dfrac{2x}{1 + x^{2}}\right)\) is equal to

(a)

\(4 \tan^{-1} x\)

(b)

0

(c)

\(\dfrac{\pi}{2}\)

(d)

\(\pi\)

Question.  35

If \(\cos^{-1} \alpha + \cos^{-1} \beta + \cos^{-1} \gamma = 3\pi\), then \(\alpha(\beta + \gamma) + \beta(\gamma + \alpha) + \gamma(\alpha + \beta)\) equals

(a)

0

(b)

1

(c)

6

(d)

12

Question.  36

The number of real solutions of the equation \(\sqrt{1 + \cos 2x} = \sqrt{2} \cos^{-1}(\cos x)\) in \([\dfrac{\pi}{2}, \pi]\) is

(a)

0

(b)

1

(c)

2

(d)

Infinite

Question.  37

If \(\cos^{-1} x > \sin^{-1} x\), then

(a)

\(\dfrac{1}{\sqrt{2}} < x \le 1\)

(b)

0 \le x < \dfrac{1}{\sqrt{2}}\)

(c)

-1 \le x < \dfrac{1}{\sqrt{2}}\)

(d)

x > 0

NCERT Exemplar Solutions Class 12 – Mathematics – Chapter 2: INVERSE TRIGONOMETRIC FUNCTIONS – Objective Type Question | Detailed Answers