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12th Grade > Mathematics

INVERSE TRIGONOMETRIC FUNCTIONS MCQs

Total Questions : 60 | Page 2 of 6 pages
Question 11. The value of cos1(cos10)=
  1.    10
  2.    4π−10
  3.    2π+10
  4.    2π−10
 Discuss Question
Answer: Option B. -> 4π−10
:
B
cos1(cos10)=cos1(cos(4π10))=4π10
Question 12. If 2tan1x=sin12x1+x2, then:
  1.    x∈R
  2.    x≥1
  3.    x≤−1
  4.    −1≤x≤1
 Discuss Question
Answer: Option D. -> −1≤x≤1
:
D
Putting θ=tan1x,π2<θ<π2, we have
R.H.S.
=sin12tanθ1+tan2θ=sin1sin2θ=2θ=2tan1x
When π22θπ2
i.e., π4θπ4
i.e., 1tanθ1
i.e.,1x1
Question 13. The set of values of p for which x2px+sin1(sin4)>0 for all real x is given by :
 
  1.    (–4,4)
  2.    (−∞,−4)∪(4,∞)
  3.    ϕ
  4.    None of these
 Discuss Question
Answer: Option C. -> ϕ
:
C
x2px+sin1(sin4)>0 for all real x.
x2px+sin1(sin4)>0
x2px+(π4)>0xϵR
D=p24(π4)<0 p2+164π<0
Since 164π>0,p2+164π cannot be negative for any value of pϵR.
Set of values of p=ϕ
Question 14. Find maximum value of x for which 2 tan1x+cos1(1x21+x2) is independent of x.
  1.    0
  2.    2
  3.    3
  4.    1
 Discuss Question
Answer: Option A. -> 0
:
A
Let x=tanθ,π2<θ<π22θ+cos1cos2θ
(i)02θ<π2cos1cos2θ=2θ
So given expression =4θ=4tan1x
(ii)π2<θ0π<2θ0cos1cos2θ=2θ
So, given expression becomes independent of θ
For π2<θ0<x0
Question 15. The value of tan2(sec13)+cot2(cosec14) is
  1.    20
  2.    21
  3.    23
  4.    25
 Discuss Question
Answer: Option C. -> 23
:
C
Let Sec13=α,cosec14=βtan2α+cot2β=91+161=23
Question 16. The value of cos1(cos 5π3)+sin1(cos 5π3) is
  1.    0
  2.    π2
  3.    2π3
  4.    10π3
 Discuss Question
Answer: Option A. -> 0
:
A
cos1(cos5π3)+sin1(cos5π3)=cos1[cos(2ππ3)]+sin1[sin(2ππ3)]=π3π3=0.
Question 17. If 3sin12x1+x24cos11x21+x2+2tan12x1+x2=π3 then x=
  1.    √3
  2.    1√3
  3.    1
  4.    None of these
 Discuss Question
Answer: Option B. -> 1√3
:
B
3sin12x1+x24cos11x21+x2+2tan12x1+x2=π3
Putting x=tanθ
3sin1(2tanθ1+tan2θ)4cos1(1tan2θ1+tan2θ)
+2tan1(2tanθ1tan2θ)=π3
3sin1(sin2θ)4cos1(cos2θ)
+2tan1(tan2θ)=π3
3(2θ)4(2θ)+2(2θ)=π36θ8θ+4θ=π3
θ=π6tan1x=π6x=tanπ6=13
Question 18. The value of sin[2tan1(13)]+cos[tan1(22)]=
  1.    1615
  2.    1415
  3.    1215
  4.    1115
 Discuss Question
Answer: Option B. -> 1415
:
B
sin[2tan1(13)]+cos[tan1(22)]
=sin[tan123119]+cos[tan1(22)]
=sin[tan134]+cos[tan122]
=tan122=cos113
Alsotan134=sin135
=35+13=1415.
Question 19. The value of cos1(cos12)sin1(sin14) is
  1.    −2
  2.    8π−26
  3.    4π+2
  4.    None of these
 Discuss Question
Answer: Option D. -> None of these
:
D
cos1(cos12)sin1(sin14)4π12+5π14=9π26
Question 20. 3cos1xπxπ2=0 has :
 
  1.    One solution
  2.    Infinite solutions
  3.    No solution
  4.    None of these
 Discuss Question
Answer: Option A. -> One solution
:
A
3cos−1x−πx−π2=0 Has : 
3cos1xπx+π2
Clearly graphs of y=3cos1x and y=πx+π2 in the domain of cos1x i.e., in [-1, 1] intersect only once, therefore there is only one solution of the given equation.

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