Page 25 - Mathematics Class - XII

Viva-Voce

1. When is inverse mapping possible?
Ans. When mapping is one-one and onto then its inverse mapping is possible.
2. What is the domain and range of sin (x + 2)?
–1

–1 .
Ans. Domain of sin (x + 2) is given by the interval [–3, –1] and range is given by the interval ,

3. Is sin (sin x) = x for all real x? 22
–1
Ans. No, sin (sin x) = x for all x ∈ [–1, 1].
–1
3
4. What is the value of sin cossin 1 ?
–1

2
1
Ans. sin –1 cossin 1 3 = sin –1 cos sin 1 .

2 3 2 6

MCQs

1. If |x| < 1 then sec [tan x] will be equal to
–1
1 x
a) b) 1+ x 2 c) 1− x 2 d)
1+ x 2 1− x 2

5 5
–1 –1 will be
2. The value of cos cos 3 + sin sin 3

10 p p 5 p
a) b) c) d) 0
3 2 3
3x 4x
1
,
3. If sin 1 sin 1 sin x then the value of x will be
5 5
a) 0, 1 b) 0, –1 c) 1, –1 d) 0, 1, –1
p
4. cos (x) + cosec (2) = , then the value of x will be
–1
–1
2
a) 3 b) 1 c) 1 d) 1
2 2 2

Answers: 1. b) 1+ x 2 2. d) 0 3. d) 0, 1, –1 4. b) 1
2

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