All Exams  >   A Level  >   Mathematics for A Level  >   All Questions

All questions of Inverse Trigonometric Functions for A Level Exam

Can you explain the answer of this question below:

  • A:

    4

  • B:

    1/4

  • C:

    2

  • D:

    none of these.

The answer is a.

Divey Sethi answered
sin θ is 3/5.
on simplifying:
(secθ + tanθ)/(secθ - tanθ)
We get, (1+sin θ)/(1-sin θ)
=(1+3/5)/(1-3/5)
=(8/2)
=4

The simplest form of for x > 0 is …​
  • a)
    x
  • b)
    -x/2
  • c)
    2x
  • d)
    x/2
Correct answer is option 'D'. Can you explain this answer?

Mira Joshi answered
tan-1(1-cosx/1+cosx)½
= tan-1{(2sin2 x/2) / (2cos2 x/2)}½
= tan-1{(2sin2 x/2) / (2cos2 x/2)}
= tan-1(tan x/2)
= x/2

Evaluate sin(3 sin–10.4)
​a)0.56
b)0.31
c)0.64
d)0.9
Correct answer is 'D'. Can you explain this answer?

3sin^-1(x) = sin^-1(3x - 4x^3) when -1/2<=x<=1/2
Definitely 0.4 comes in this range of x and so
3sin^-1(0.4) = sin^-1[3*0.4 - 4*0.4^3]
3sin^-1(0.4) = sin^-1[1.2 - 4*0.064]
3sin^-1(0.4) = sin^-1[1.2 - 0.256]
3sin^-1(0.4) = sin^-1[0.944]
Finally , sin(3sin^-1(0.4)) = sin{sin^-1(0.944)} = 0.944

The maximum value of sin x + cos x is
  • a)
    1
  • b)
    2
  • c)
    √2
  • d)
Correct answer is option 'C'. Can you explain this answer?

Shreya Gupta answered
sinx + cosx=sinx + sin(90-x)=2sin{(x+90-x)/2}cos{(x-90+x)/2}using the formula 

The value ofcos150−sin150 is
  • a)
  • b)
  • c)
    0
  • d)
     
Correct answer is option 'D'. Can you explain this answer?

Poojan Angiras answered
Heyy!!! write cos 15 and sin 15 as cos(60-45) and sin(60-45) respectively.And then apply formula of cos(a+b) and sin(a+b).Proceed as the question u will get correct answer :-):-)^_^

Evaluate :cos (tan–1 x)
  • a)
  • b)
  • c)
  • d)
Correct answer is option 'B'. Can you explain this answer?

Preeti Iyer answered
tan−1 x = θ , so that  x=tanθ . We need to determine  cosθ .
sec2θ = 1 + tan2θ = 1 + x2 
∴s ecθ = ±√(1+x2
Then, cos(tan−1x) = cosθ=1/secθ = ±1/√(1+x2)

  • a)
    4
  • b)
    1/4
  • c)
    2
  • d)
    none of these.
Correct answer is option 'A'. Can you explain this answer?

Krishna Iyer answered
sin θ is 3/5.
on simplifying:
(secθ + tanθ)/(secθ - tanθ)
We get, (1+sin θ)/(1-sin θ)
=(1+3/5)/(1-3/5)
=(8/2)
=4

If ab + bc + ca = 0, then find 1/a2-bc + 1/b2 – ca + 1/c2- ab
  • a)
    π
  • b)
    0
  • c)
    -1
  • d)
Correct answer is option 'B'. Can you explain this answer?

Preeti Iyer answered
Given ab+bc+ca=0 and asked to find value 1/(a2-bc ) + 1/(c2-ab) + 1/(a2-bc)Put -ac = ab + bc ; -ab = ac+ bc and -bc =ab + 

The number of solutions of the equation sin-1 x - cos-1 x = sin-1(1/2) is
a) 3
b) 1
c) 2
d) infinite.
Correct answer is option 'B'. Can you explain this answer?

Solution:

Given equation is sin^-1(x) - cos^-1(x) = sin^-1(1/2)

We know that sin(x) + cos(x) = √2 cos(x - π/4)

So, sin^-1(x) - cos^-1(x) = π/2 - sin^-1(√2x)

Therefore, the given equation becomes π/2 - sin^-1(√2x) = sin^-1(1/2)

sin(sin^-1(x)) = xsin(π/2 - sin^-1(√2x)) = √[1 - 2x^2]

√[1 - 2x^2] = 1/2

2x^2 = 3/4

x = ±√3/2

Therefore, the given equation has only 1 solution, which is x = √3/2 or x = -√3/2.

Hence, the correct answer is option B.

Evaluate sin(3 sin–1 0.4)​
  • a)
    0.9
  • b)
    0.31
  • c)
    0.64
  • d)
    0.56
Correct answer is option 'D'. Can you explain this answer?

Mohit Rajpoot answered
3sin^-1(x) = sin^-1(3x - 4x^3) when -1/2<=x<=1/2
Definitely 0.4 comes in this range of x and so
3sin^-1(0.4) = sin^-1[3*0.4 - 4*0.4^3]
3sin^-1(0.4) = sin^-1[1.2 - 4*0.064]
3sin^-1(0.4) = sin^-1[1.2 - 0.256]
3sin^-1(0.4) = sin^-1[0.944]
Finally , sin(3sin^-1(0.4)) = sin{sin^-1(0.944)} = 0.944

 is equal to
  • a)
  • b)
  • c)
  • d)
Correct answer is 'C'. Can you explain this answer?

Nikita Singh answered
Let y = tan−1[(a−x)/(a+x)]1/2
put x = a cos θ
Now, y = tan−1[(a − a cos θ)/(a + a cos θ)]1/2
⇒ y = tan−1((1 − cos θ)/(1 + cos θ))1/2
⇒ y = tan−1[[(1−cos θ)(1−cos θ)]/(1+cos θ)(1−cos θ)]1/2
⇒ y = tan−1[(1−cos θ)2/1 − cos2θ]1/2
⇒ y = tan−1[(1 − cos θ)/sin θ]
⇒ y = tan−1[2 sin2(θ/2)/2 sin(θ/2) . cos(θ/2)]
⇒ y = tan−1[tan(θ/2)]
⇒ y = θ/2
⇒ y = 1/2 cos−1(x/a)

  • a)
  • b)
    1
  • c)
    0
  • d)
    none of these.
Correct answer is option 'B'. Can you explain this answer?

Nikita Singh answered
sin-1√3/5 = A
Sin A = √3/5 , cos A = √22/5 
Therefore Cos-1√3/5 = B
Cos B = √3/5 , sin B = √22/5  
sin(A+B) = sinA cosB + cosA sinB
= √3/5 * √3/5 + √22/5 * √22/5
= 3/25 * 22/25
= 25/25 
= 1

  • a)
    ±√3.
  • b)
    0
  • c)
  • d)
    1
Correct answer is option 'D'. Can you explain this answer?

Devendra Singh answered
Apply apply formula of Sin inverse X + Cos inverse X and the question will be solved

  • a)
    4
  • b)
    1/4
  • c)
    2
  • d)
    none of these.
Correct answer is 'A'. Can you explain this answer?

SinQ is 3/5.
on simplifying:
(secQ+tanQ)/(secQ-tanQ)
We get...(1+sinQ)/(1-sinQ)
=(1+3/5)/(1-3/5)
=(8/2)
=4

Evaluate: sin (2 sin–10.6)​
  • a)
    0.6
  • b)
    0.66
  • c)
    0.36
  • d)
    0.96
Correct answer is option 'D'. Can you explain this answer?

Nikita Singh answered
Let, sin-1(0.6) = A…………(1)
  ( Since, sin² A + cos² A = 1 ⇒ sin² A = 1 - cos² A ⇒ sin A = √(1-cos² A) )

The simplest form of 
  • a)
  • b)
  • c)
    2x
  • d)
Correct answer is option 'A'. Can you explain this answer?

Top Rankers answered
(cosx−sinx)/(cosx+sinx) = (1−tanx)/(1+tanx) 
tan(A−B) = (tanA−tanB)/(1 + tanAtanB)
= tan(π/4−x)
putting this value in question.
tan−1tan(π/4−x)
π/4−x.

Evaluate 
  • a)
  • b)
  • c)
  • d)
Correct answer is 'A'. Can you explain this answer?

Knowledge Hub answered
Correct Answer :- a
Explanation : cos-1(12/13) + sin-1 (3/5)
⇒ sin-1 5/13 + sin-1 3/5 
Using the formula,  sin-1x +  sin-1y = sin-1( x√1-y² + y√1-x² )
⇒ sin-1 ( 5/13√1-9/25 + 3√1-25/169)
⇒ sin-1 ( 5/13 × 4/5 + 3/5 × 12/13)
⇒ sin-1 (30 + 36 / 65)
⇒ sin-1 (56/ 65)

What is the maximum and minimum value of sin x +cos x?
  • a)
    0, -1
  • b)
    1, 0
  • c)
    -1, -√2
  • d)
    √2, –√2
Correct answer is option 'D'. Can you explain this answer?

Rajiv Reddy answered
Let y= sin x + cos x
dy/dx=cos x- sin x
For maximum or minimum dy/dx=0
Setting cosx- sin x=0
We get cos x = sin x
x= π/4, 5π/4———-
Whether these correspond to maximum or minimum, can be found from the sign of second derivative.
d^2y/dx^2=-sin x - cos x=-1/√2–1/√2 (for x=π/4) which is negative. Hence x=π/4 corresponds to maximum.For x=5π/4
d^2y/dx^2=-(-1/√2)-(-1/√2)=2/√2 a positive quantity. Hence 5π/4 corresponds to minimum
Maximum value of the function
y= sin π/4 + cos π/4= 2/√2=√2
Minimum value is
Sin(5π/4)+cos (5π/4)=-2/√2=-√2

If 2tan−1(cos x) = tan−1(2cosecx) , then x =
  • a)
  • b)
  • c)
  • d)
    none of these.
Correct answer is option 'B'. Can you explain this answer?

If 2 tan-1 (cos x) = tan -1(2 cosec x),
2tan-1(cos x) = tan-1 (2 cosec x)
= tan-1(2 cosec x) 
= cot x cosec x = cosec x = x = π/4

sin (200)0 + cos (200)0 is
  • a)
    Zero
  • b)
    Positive
  • c)
    Zero or positive.
  • d)
    Negative
Correct answer is option 'D'. Can you explain this answer?

Dipika Dey answered
To determine the sign of sin(200)0 and cos(200)0, we need to recall the unit circle and the values of sine and cosine for angles in the different quadrants.

The unit circle is a circle with a radius of 1 unit, centered at the origin (0,0) on a coordinate plane. It helps us understand the relationship between angles and the coordinates on the circle.

The circle is divided into four quadrants: Quadrant I (0°-90°), Quadrant II (90°-180°), Quadrant III (180°-270°), and Quadrant IV (270°-360°).

In Quadrant I, both the x-coordinate (cosine) and the y-coordinate (sine) are positive. In Quadrant II, the x-coordinate (cosine) is negative, but the y-coordinate (sine) is positive. In Quadrant III, both the x-coordinate (cosine) and the y-coordinate (sine) are negative. In Quadrant IV, the x-coordinate (cosine) is positive, but the y-coordinate (sine) is negative.

Now let's consider the given angle, 200°.

Since 200° is greater than 180°, it lies in Quadrant III.

- The cosine of 200° will be negative because it is in Quadrant III.
- The sine of 200° will also be negative because it is in Quadrant III.

Hence, sin(200)0 and cos(200)0 are both negative.

Therefore, the correct answer is option 'D' - Negative.

The number of solutions of the equation 
  • a)
    One
  • b)
    two
  • c)
    more than one
  • d)
    none of these.
Correct answer is option 'A'. Can you explain this answer?

Nilesh Goyal answered
As no value of x in (0, 1) can satisfy the given equation.Thus, the given equation has only one solution.

If sin A + cos A = 1, then sin 2A is equal to
  • a)
    2
  • b)
    0
  • c)
    1/2
  • d)
    1
Correct answer is option 'B'. Can you explain this answer?

Anjali Sen answered
Understanding the Given Equation
We start with the equation:
- sinA + cosA = 1
This can be analyzed using the Pythagorean identity for sine and cosine.
Squaring Both Sides
If we square both sides:
- (sinA + cosA)^2 = 1^2
- sin²A + 2sinAcosA + cos²A = 1
Using the identity sin²A + cos²A = 1, we replace it in the equation:
- 1 + 2sinAcosA = 1
This simplifies to:
- 2sinAcosA = 0
Finding Values of Sine and Cosine
From 2sinAcosA = 0, we can conclude:
- sinA = 0 or cosA = 0
This means A can be:
- A = nπ (where n is an integer) for sinA = 0.
- A = π/2 + nπ for cosA = 0.
Calculating Sin 2A
We know that:
- sin 2A = 2sinAcosA
Given that either sinA = 0 or cosA = 0, we have:
- If sinA = 0, then sin 2A = 2 * 0 * cosA = 0.
- If cosA = 0, then sin 2A = 2 * sinA * 0 = 0.
In both scenarios, we find that:
- sin 2A = 0
Conclusion
Thus, the value of sin 2A is:
- 0
Therefore, the correct answer is option 'B'.

Chapter doubts & questions for Inverse Trigonometric Functions - Mathematics for A Level 2025 is part of A Level exam preparation. The chapters have been prepared according to the A Level exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for A Level 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.

Chapter doubts & questions of Inverse Trigonometric Functions - Mathematics for A Level in English & Hindi are available as part of A Level exam. Download more important topics, notes, lectures and mock test series for A Level Exam by signing up for free.

Mathematics for A Level

124 videos|166 docs|207 tests

Top Courses A Level