If $\sec^{-1}(x) + \tan^{-1}\sqrt{9y^2-1} + \sin^{-1}(x^2+y^2) = \lambda$ has no solution, then exhaustive set of values of $\lambda$ is equal to:
Step-by-Step Solution
Key Concept: Domain and range of inverse trigonometric functions
Step 1: Determine the domain constraints for $\sec^{-1}(x)$.
For $\sec^{-1}(x)$ to be defined, we require:
$$|x| \geq 1$$
Step 2: Determine the domain constraints for $\tan^{-1}\sqrt{9y^2-1}$.
For the expression under the square root to be non-negative:
$$9y^2 - 1 \geq 0$$
$$9y^2 \geq 1$$
$$|y| \geq \frac{1}{3}$$
Step 3: Determine the domain constraints for $\sin^{-1}(x^2+y^2)$.
For $\sin^{-1}(x^2+y^2)$ to be defined, the argument must lie in $[-1, 1]$. Since $x^2 + y^2 \geq 0$, we need:
$$0 \leq x^2 + y^2 \leq 1$$
Step 4: Find the intersection of all domain constraints.
From Step 1: $|x| \geq 1$ implies $x^2 \geq 1$
Therefore: $x^2 + y^2 \geq 1 + y^2 \geq 1$
Combined with the constraint from Step 3 that $x^2 + y^2 \leq 1$, we must have:
$$x^2 + y^2 = 1$$
This means $y^2 = 1 - x^2 = 0$, so $y = 0$ and $x = \pm 1$.
Step 5: Check if the solution satisfies all constraints.
When $x = \pm 1$ and $y = 0$:
- The constraint $|x| \geq 1$ is satisfied ✓
- The constraint $|y| \geq \frac{1}{3}$ requires $|0| \geq \frac{1}{3}$, which is **NOT satisfied** ✗
Step 6: Conclude about the solution set.
Since there are no values of $x$ and $y$ that simultaneously satisfy all three domain constraints, the domain of the left-hand side is empty. Therefore, the equation has no solution for **any value of $\lambda$**.
The exhaustive set of values of $\lambda$ for which the equation has no solution is $\mathbb{R}$.
**Final Answer: Option 1** — $\mathbb{R}$
Correct Answer: 1