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CUET · MATHS · PYQ PAPER 2023

If \(\cos ^{-1} \alpha+\cos ^{-1} \beta+\cos ^{-1} \gamma=3 \pi\) then the value of \(\alpha^2 \beta^2 \gamma^2+3(\alpha+\beta+\gamma)\) is:

  1. A -8
  2. B \(0\)
  3. C 10
  4. D -10
Verified Solution

Answer & Solution

Correct Answer

(A) -8

Step-by-step Solution

Detailed explanation

Given: \( \cos^{-1} \alpha+\cos^{-1} \beta+\cos^{-1} \gamma=3 \pi \) Since \( 0 \le \cos^{-1} x \le \pi \), it implies: \( \cos^{-1} \alpha = \pi \implies \alpha = -1 \) \( \cos^{-1} \beta = \pi \implies \beta = -1 \) \( \cos^{-1} \gamma = \pi \implies \gamma = -1 \) Value of…