Mathematics · Inverse Trigonometric Functions

JEE Main 2024 — 9 April, Shift 1 — Question 11

If the domain of the function f(x)=sin⁡−1(x−12x+3)f(x)=\sin ^{-1}\left(\frac{x-1}{2 x+3}\right) is R−(α,β)R-(\alpha, \beta) then 12αβ12 \alpha \beta is equal to :

  1. Option A:

    36

  2. Option B:

    24

  3. Option C:

    40

  4. Option D:

    32

    Correct

Answer: D

Step-by-step solution

Domain of f(x)=sin⁡−1(x−12x+3)f(x)=\sin ^{-1}\left(\frac{x-1}{2 x+3}\right) is

2x+3≠0&x≠−322 x+3 \neq 0 \& x \neq \frac{-3}{2} and ∣(x−1)2x+3∣≤1\left|\frac{(x-1)}{2 x+3}\right| \leq 1

∣x−1∣≤∣2x+3∣|x-1| \leq|2 x+3|

For ∣2x+3∣≥∣x−1∣|2 x+3| \geq|x-1|

x∈(−∞,−4]∪(−23,∞)x \in(-\infty,-4] \cup\left(-\frac{2}{3}, \infty\right)

α=−4&β=−23:12αβ=32\alpha=-4 \& \beta=-\frac{2}{3}: 12 \alpha \beta=32

figure

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Mathematics
Chapter
Inverse Trigonometric Functions
Topic
Introduction to Inverse Trigonometric Functions