CUET UG Mathematics Booster Test 2 - Properties of Inverse Trigonometric Functions
📌 Answers are locked once submitted — results and explanations appear at the end.
QUESTION 1 OF 20
If a variable x is stated to lie within the mathematical domain of cosec⁻¹, which of the following is an impossible evaluation value for x?
QUESTION 2 OF 20
Assertion (A): Trigonometric functions must be explicitly restricted to specific domains to become strictly invertible.
Reason (R): The inverse function y = cosec⁻¹ x has a bounded principal range of exactly [-1, 1].
QUESTION 3 OF 20
Analytically evaluate the numerical value of cosec⁻¹(-√2) and identify if it lies within the standard principal branch.
QUESTION 4 OF 20
Logically arrange the domains/ranges related to the cosecant functions from the broadest covering of the real number line to the narrowest constrained interval:
1. Natural Domain of cosec x
2. Domain of cosec⁻¹ x
3. Principal Range of cosec⁻¹ x
QUESTION 5 OF 20
Which of the following statements is mathematically incorrect regarding the domain of sec⁻¹?
QUESTION 6 OF 20
Analyzing the graph of y = sec⁻¹x, as x approaches infinity continuously, what specific value does the curve asymptotically approach within the bounds of its restricted range?
QUESTION 7 OF 20
Which of the following strict evaluations correspond perfectly to points inside the principal range of sec⁻¹?
(i) sec⁻¹(1) = 0
(ii) sec⁻¹(-1) = π
QUESTION 8 OF 20
Match the inverse trigonometric function to the specific point of discontinuity within its principal value branch.
| List 1 | List 2 |
|---|---|
| 1. cosec⁻¹ | a. None |
| 2. sec⁻¹ | b. 0 |
| 3. tan⁻¹ | c. π/2 |
QUESTION 9 OF 20
A continuous random variable X is normally distributed from -∞ to ∞. If y = tan⁻¹(X) is computed for any valid draw, what is the theoretical probability that y successfully evaluates to a real number?
QUESTION 10 OF 20
If a moving average filter tracks a signal defined by y = tan⁻¹x as the input x approaches positive infinity, what exact asymptotic value does the data converge to?
QUESTION 11 OF 20
In standard mathematics, what is the theoretical probability that the strict principal value of tan⁻¹(1) equals exactly π/4?
QUESTION 12 OF 20
Comparing the area of the region bounded by x=0, x=1, and y=tan⁻¹x in the principal branch (-π/2, π/2) against the adjacent restricted branch (π/2, 3π/2), what is the absolute difference in height of these corresponding curve points at x=1?
QUESTION 13 OF 20
Consider the integral conceptually. Because the domain of y=cot⁻¹x is R, if one integrates this decreasing function from x=0 to positive infinity, the curve begins identically at cot⁻¹(0). What is cot⁻¹(0)?
QUESTION 14 OF 20
Analytically evaluate the sum expression: tan⁻¹(1) + cos⁻¹(-1/2) + sin⁻¹(-1/2) utilizing their proper principal ranges.
QUESTION 15 OF 20
An analytical case study involves precisely calculating the value of cot⁻¹(-1). What is its mathematically defined principal value?
QUESTION 16 OF 20
Assertion (A): The inverse of cotangent can be mathematically defined on multiple separate intervals like (0, π), (π, 2π), and (-π, 0).
Reason (R): The original cotangent function restricted to any of these exact intervals is bijective, which ensures an inverse naturally exists.
QUESTION 17 OF 20
Match the graphical characteristic with the corresponding inverse trigonometric function.
| List I | List II |
|---|---|
| 1. Horizontal asymptotes at \(y=\pm \frac{\pi }{2}\) | a. \(y={cot}^{-1}x\) |
| 2. Horizontal asymptotes at \(y=0\) and \(y=\pi\) | b. \(y={tan}^{-1}x\) |
| 3. Strictly increasing function on its domain | c. Graph decreases from left to right |
| 4. Strictly decreasing function on its domain | d. Graph increases from left to right |
QUESTION 18 OF 20
Arrange the following specific functions and evaluations based on their exact values from lowest to highest:
1. sin⁻¹(0)
2. cot⁻¹(0)
3. cos⁻¹(-1)
QUESTION 19 OF 20
QUESTION 20 OF 20
Test Complete!
Answer Review
1 If a variable x is stated to lie within the mathematical domain of cosec⁻¹, which of the following is an impossible evaluation value for x?
Domain of cosec⁻¹x is |x| ≥ 1. Values between −1 and 1 are excluded. Hence 1/2 is impossible.
The inverse cosecant function is defined only for: x ≤ −1 or x ≥ 1. Thus values strictly between −1 and 1 are excluded from the domain. Among the options, 1/2 lies inside the forbidden interval (−1,1). Therefore cosec⁻¹(1/2) is undefined. Hence option B is correct.
- Option A → 2 satisfies |x| ≥ 1.
- Option C → −1.5 belongs to valid domain.
- Option D → √2 is greater than 1, hence valid.
Used: Elimination
Application:
- Reject values not satisfying |x| ≥ 1.
Final Logic:
- Only 1/2 lies inside excluded interval.
"cosec inverse lives outside ±1."
2 Assertion (A): Trigonometric functions must be explicitly restricted to specific domains to become strictly invertible.
Reason (R): The inverse function y = cosec⁻¹ x has a bounded principal range of exactly [-1, 1].
Inverse requires bijective function. Domain restriction ensures one-one behavior. cosec⁻¹ range is not [-1,1].
Inverse trigonometric functions require restricted domains so the original function becomes bijective. Hence the assertion is true. However, the principal range of cosec⁻¹x is: [-π/2, π/2] − {0}, not [-1,1]. Therefore the reason is false. Hence option B is correct.
- Option A → Assertion is mathematically true.
- Option C → Reason itself is incorrect.
- Option D → Assertion is not false.
Used: Elimination
Application:
- Check assertion and reason independently.
Final Logic:
- Restriction true, stated range false.
"Angles use π, not ±1."
3 Analytically evaluate the numerical value of cosec⁻¹(-√2) and identify if it lies within the standard principal branch.
cosec(−π/4)=−√2. −π/4 lies in principal branch. Therefore value is valid.
We seek θ such that: cosecθ=−√2. Since: sinθ=−1/√2, the principal value is: θ=−π/4. This lies in: [-π/2, π/2]−{0}, the principal branch of cosec⁻¹x. Hence option A is correct.
- Option B → Sign is incorrect.
- Option C → 3π/4 is outside principal branch.
- Option D → cosec(−π/2)=−1, not −√2.
Used: Substitution
Application:
- Convert cosecant to sine relation.
Final Logic:
- sin(−π/4)=−1/√2 gives cosec value −√2.
"√2 links with π/4."
4 Logically arrange the domains/ranges related to the cosecant functions from the broadest covering of the real number line to the narrowest constrained interval:
1. Natural Domain of cosec x
2. Domain of cosec⁻¹ x
3. Principal Range of cosec⁻¹ x
Natural domain covers most reals. Inverse domain is more restricted. Principal range is narrowest interval.
Natural domain of cosec x includes all real numbers except integral multiples of π. The domain of cosec⁻¹x is narrower: R−(−1,1). Its principal range: [-π/2,π/2]−{0} is even more restricted. Therefore correct ordering is: 1,2,3. Hence option C is correct.
- Option A → Reverses broadest and narrowest sets.
- Option B → Domain of inverse is not broadest.
- Option D → Principal range is narrowest, not middle.
Used: Option Grouping
Application:
- Compare interval sizes conceptually.
Final Logic:
- Natural domain > inverse domain > principal range.
"Original bigger, inverse smaller, branch smallest."
5 Which of the following statements is mathematically incorrect regarding the domain of sec⁻¹?
sec⁻¹x domain requires |x| ≥ 1. Zero lies inside excluded interval. Hence 0 is invalid.
The domain of sec⁻¹x is: x ≤ −1 or x ≥ 1. Thus all values between −1 and 1, including 0, are excluded. Therefore statement D is incorrect. Statements A, B, and C are mathematically correct. Hence option D is correct.
- Option A → Correct domain representation.
- Option B → Properly describes excluded interval.
- Option C → sec⁻¹ and cosec⁻¹ share same domain structure.
Used: Elimination
Application:
- Check whether each option satisfies |x| ≥ 1.
Final Logic:
- 0 violates sec inverse domain condition.
"sec inverse avoids center interval."
6 Analyzing the graph of y = sec⁻¹x, as x approaches infinity continuously, what specific value does the curve asymptotically approach within the bounds of its restricted range?
sec y approaches infinity near π/2. π/2 excluded from range. Curve approaches it asymptotically.
For sec⁻¹x: range is [0,π]−{π/2}. As x→∞, the corresponding angle approaches π/2 because: sec(π/2) becomes unbounded. However π/2 itself is excluded. Therefore the curve asymptotically approaches π/2. Hence option D is correct.
- Option A → sec0=1, not infinity.
- Option B → secπ=−1 only.
- Option C → Not in sec inverse principal range.
Used: Contextual/Tonal Matching
Application:
- Relate secant growth with asymptotic angle.
Final Logic:
- Large secant values occur near π/2.
"Huge secant hugs π/2."
7 Which of the following strict evaluations correspond perfectly to points inside the principal range of sec⁻¹?
(i) sec⁻¹(1) = 0
(ii) sec⁻¹(-1) = π
sec0=1. secπ=−1. Both angles lie in principal branch.
The principal range of sec⁻¹x is: [0,π]−{π/2}. Now: sec0=1 ⇒ sec⁻¹(1)=0, secπ=−1 ⇒ sec⁻¹(−1)=π. Both outputs belong to the principal range. Therefore both statements are correct. Hence option C is correct.
- Option A → Ignores valid second statement.
- Option B → Ignores valid first statement.
- Option D → Both evaluations are standard identities.
Used: Substitution
Application:
- Evaluate secant at boundary angles.
Final Logic:
- 0 and π both belong to sec inverse range.
"Positive one at 0, negative one at π."
8 Match the inverse trigonometric function to the specific point of discontinuity within its principal value branch.
| List 1 | List 2 |
|---|---|
| 1. cosec⁻¹ | a. None |
| 2. sec⁻¹ | b. 0 |
| 3. tan⁻¹ | c. π/2 |
cosec⁻¹ excludes 0. sec⁻¹ excludes π/2. tan⁻¹ has no discontinuity in range.
For principal branches: cosec⁻¹ excludes 0 from its range, sec⁻¹ excludes π/2, tan⁻¹ has continuous range: (−π/2,π/2). Hence matching becomes: 1-b, 2-c, 3-a. Therefore option D is correct.
- Option A → Assignments reversed incorrectly.
- Option B → tan⁻¹ has no excluded interior point.
- Option C → sec⁻¹ discontinuity wrongly matched.
Used: Option Grouping
Application:
- Associate each inverse function with excluded angle.
Final Logic:
- cosec→0, sec→π/2, tan→none.
"cosec skips 0, sec skips π/2."
9 A continuous random variable X is normally distributed from -∞ to ∞. If y = tan⁻¹(X) is computed for any valid draw, what is the theoretical probability that y successfully evaluates to a real number?
tan⁻¹x defined for all real x. Every normal draw is valid. Probability equals 1.
The inverse tangent function has domain: R. A normally distributed variable can take any real value, and tan⁻¹x is defined for every real number. Therefore every possible draw produces a valid real output. Hence probability equals 1. Option D is correct.
- Option A → tan inverse never becomes undefined on reals.
- Option B → No restriction eliminates half the values.
- Option C → Probability cannot be negative.
Used: Elimination
Application:
- Use complete real-number domain property.
Final Logic:
- All real inputs are valid for tan⁻¹x.
"tan inverse accepts every real."
10 If a moving average filter tracks a signal defined by y = tan⁻¹x as the input x approaches positive infinity, what exact asymptotic value does the data converge to?
tan⁻¹x has horizontal asymptote π/2. As x→∞, output approaches π/2. Value never exceeds π/2.
The principal range of tan⁻¹x is: (−π/2,π/2). As x increases indefinitely, tan⁻¹x approaches π/2 asymptotically. The graph gets closer and closer to π/2 without touching it. Therefore the limiting value is π/2. Hence option C is correct.
- Option A → tan⁻¹(∞) is not 0.
- Option B → π lies outside principal range.
- Option D → Negative asymptote occurs as x→−∞.
Used: Contextual/Tonal Matching
Application:
- Recall asymptotic behavior of tan inverse graph.
Final Logic:
- Positive infinity maps toward π/2.
"Big positive tan inverse → π/2."
11 In standard mathematics, what is the theoretical probability that the strict principal value of tan⁻¹(1) equals exactly π/4?
tan(π/4)=1. Principal range contains π/4. Therefore tan⁻¹(1)=π/4 always.
The inverse tangent function has principal range: (-π/2, π/2). Since: tan(π/4)=1, the principal value becomes: tan⁻¹(1)=π/4. This equality is always true, so the probability is 1. Hence option B is correct.
- Option A → No uncertainty exists in deterministic evaluation.
- Option C → Statement is not false mathematically.
- Option D → Random probability interpretation is incorrect here.
Used: Substitution
Application:
- Use standard tangent identity directly.
Final Logic:
- tan⁻¹(1) always equals π/4.
"tan one gives π/4."
12 Comparing the area of the region bounded by x=0, x=1, and y=tan⁻¹x in the principal branch (-π/2, π/2) against the adjacent restricted branch (π/2, 3π/2), what is the absolute difference in height of these corresponding curve points at x=1?
Adjacent tangent branches differ by π. tan periodicity shifts outputs vertically. Difference in heights equals π.
The tangent function has period π. Hence inverse tangent values from adjacent branches differ by π. At x=1: principal branch gives π/4, adjacent branch gives 5π/4. Difference: 5π/4−π/4=π. Therefore option A is correct.
- Option B → Half the actual branch difference.
- Option C → Tangent repeats after π, not 2π.
- Option D → Adjacent branches are vertically shifted.
Used: Contextual/Tonal Matching
Application:
- Use tangent periodicity property.
Final Logic:
- Adjacent inverse branches differ by π.
"Tan branches jump by π."
13 Consider the integral conceptually. Because the domain of y=cot⁻¹x is R, if one integrates this decreasing function from x=0 to positive infinity, the curve begins identically at cot⁻¹(0). What is cot⁻¹(0)?
cot(π/2)=0. π/2 lies in principal range (0,π). Hence cot⁻¹(0)=π/2.
For cot⁻¹x, the principal range is: (0,π). We require an angle θ satisfying: cotθ=0. Since: cot(π/2)=0, the principal value is: π/2. Thus option C is correct.
- Option A → cot0 is undefined.
- Option B → cotπ is undefined.
- Option D → cot⁻¹(0) exists and equals π/2.
Used: Substitution
Application:
- Recall standard cotangent values.
Final Logic:
- Only π/2 produces cotangent zero.
"cot zero-cross occurs at π/2."
14 Analytically evaluate the sum expression: tan⁻¹(1) + cos⁻¹(-1/2) + sin⁻¹(-1/2) utilizing their proper principal ranges.
tan⁻¹(1)=π/4. cos⁻¹(−1/2)=2π/3. sin⁻¹(−1/2)=−π/6.
Evaluate each principal value: tan⁻¹(1)=π/4, cos⁻¹(−1/2)=2π/3, sin⁻¹(−1/2)=−π/6. Adding: π/4 + 2π/3 − π/6 = π/4 + π/2 = 3π/4. Hence option A is correct.
- Option B → Ignores cosine contribution properly.
- Option C → Overestimates final sum.
- Option D → Uses incorrect principal branch values.
Used: Substitution
Application:
- Use standard inverse trigonometric values.
Final Logic:
- Correct principal values sum to 3π/4.
"¼ + ½ = ¾."
15 An analytical case study involves precisely calculating the value of cot⁻¹(-1). What is its mathematically defined principal value?
Principal range of cot⁻¹ is (0,π). cot(3π/4)=−1. Hence cot⁻¹(−1)=3π/4.
We seek θ in the principal range: (0,π), such that: cotθ=−1. Since: cot(3π/4)=−1, the principal value is: 3π/4. Thus option B is correct.
- Option A → Outside principal range.
- Option C → Gives positive cotangent value.
- Option D → Lies outside defined principal branch.
Used: Elimination
Application:
- Reject values outside principal range first.
Final Logic:
- 3π/4 uniquely satisfies cotθ=−1.
"Negative cot lies in second quadrant."
16 Assertion (A): The inverse of cotangent can be mathematically defined on multiple separate intervals like (0, π), (π, 2π), and (-π, 0).
Reason (R): The original cotangent function restricted to any of these exact intervals is bijective, which ensures an inverse naturally exists.
cotangent is periodic with period π. Each interval gives one-one behavior. Hence inverse branches exist.
Cotangent becomes bijective on any interval of length π avoiding discontinuities. Therefore intervals like: (0,π), (π,2π), (−π,0) all produce valid inverse branches. The reason correctly explains why multiple inverse branches exist. Hence option C is correct.
- Option A → Both statements are mathematically true.
- Option B → Reason correctly explains assertion.
- Option D → Assertion is not false.
Used: Contextual/Tonal Matching
Application:
- Use bijection requirement for inverse existence.
Final Logic:
- Restricted bijective branches create inverse functions.
"One π interval = one cot branch."
17 Match the graphical characteristic with the corresponding inverse trigonometric function.
| List I | List II |
|---|---|
| 1. Horizontal asymptotes at \(y=\pm \frac{\pi }{2}\) | a. \(y={cot}^{-1}x\) |
| 2. Horizontal asymptotes at \(y=0\) and \(y=\pi\) | b. \(y={tan}^{-1}x\) |
| 3. Strictly increasing function on its domain | c. Graph decreases from left to right |
| 4. Strictly decreasing function on its domain | d. Graph increases from left to right |
\({tan}^{-1}x\) has horizontal asymptotes at \(y=\pm \frac{\pi }{2}\). \({cot}^{-1}x\) has horizontal asymptotes at \(y=0\) and \(y=\pi\). \({tan}^{-1}x\) is strictly increasing. \({cot}^{-1}x\) is strictly decreasing.
According to the NCERT graphs: List I — List II 1. Horizontal asymptotes at \(y=\pm \frac{\pi }{2}\) — b. \(y={tan}^{-1}x\) 2. Horizontal asymptotes at \(y=0\) and \(y=\pi\) — a. \(y={cot}^{-1}x\) 3. Strictly increasing function — d. Graph increases from left to right 4. Strictly decreasing function — c. Graph decreases from left to right The graph of \(y={tan}^{-1}x\) increases continuously from left to right and approaches \(y=-\frac{\pi }{2}\)as \(x\rightarrow -\infty\) and \(y=\frac{\pi }{2}\)as \(x\rightarrow \infty\). The graph of \(y={cot}^{-1}x\) decreases continuously from left to right and approaches \(y=\pi\) as \(x\rightarrow -\infty\) and \(y=0\) as \(x\rightarrow \infty\). Therefore, the correct matching is: 1 → b 2 → a 3 → d 4 → c Hence, Option A is correct.
- Option B → Incorrect because the asymptotes of \({tan}^{-1}x\) and \({cot}^{-1}x\) are interchanged.
- Option C → Incorrect because the increasing and decreasing graph characteristics are interchanged.
- Option D → Incorrect because both the asymptotes and monotonicity are mismatched.
Used
- Option Grouping
Application:
- First identify the asymptotes of each inverse trigonometric function, then match their increasing/decreasing nature.
Final Logic:
- \({tan}^{-1}x\)→ Increasing → Asymptotes \(\pm \frac{\pi }{2}\)
- \({cot}^{-1}x\)→ Decreasing → Asymptotes \(0,\pi\)
"Tan rises to ±π/2; Cot falls from π to 0."
18 Arrange the following specific functions and evaluations based on their exact values from lowest to highest:
1. sin⁻¹(0)
2. cot⁻¹(0)
3. cos⁻¹(-1)
sin⁻¹(0)=0. cot⁻¹(0)=π/2. cos⁻¹(−1)=π.
Evaluate each quantity: sin⁻¹(0)=0, cot⁻¹(0)=π/2, cos⁻¹(−1)=π. Thus ordering from smallest to largest becomes: 0 < π/2 < π. Hence arrangement: 1, 2, 3. Therefore option D is correct.
- Option A → Reverses actual order completely.
- Option B → π/2 cannot exceed π.
- Option C → π cannot be smaller than π/2.
Used: Substitution
Application:
- Compute exact principal values.
Final Logic:
- 0 < π/2 < π gives sequence 1,2,3.
"0, half π, full π."
19
sin⁻¹ accepts values from −1 to 1. This interval forms its domain. Mentioned directly in passage.
The passage explicitly states: sin⁻¹ has domain: [-1,1] and range: [-π/2,π/2]. Therefore the correct domain of the principal inverse sine function is: [-1,1]. Hence option A is correct.
- Option B → This is the principal range, not domain.
- Option C → sin⁻¹ is not defined for all reals.
- Option D → Interval belongs to cosine inverse range.
Used: Contextual/Tonal Matching
Application:
- Read directly from passage statement.
Final Logic:
- Passage explicitly defines domain as [-1,1].
"sin inverse input stays within ±1."
20
Value inside principal branch has special name. NCERT calls it principal value. Mentioned directly in passage.
The passage clearly defines: "The value of an inverse trigonometric function which lies in the range of principal branch is called the principal value." Therefore the required term is: Principal value. Hence option A is correct.
- Option B → Not a standard mathematical term here.
- Option C → Refers to modulus, unrelated concept.
- Option D → Too generic and undefined in NCERT context.
Used: Contextual/Tonal Matching
Application:
- Identify exact terminology from passage.
Final Logic:
- NCERT directly names it "principal value."
"Inside principal branch = principal value."
