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GUJCET · Maths · Determinants
If \(D =\left|\begin{array}{ccc}1 & -\cos \theta & -1 \\ \cos \theta & 1 & -\cos \theta \\ 1 & \cos \theta & 1\end{array}\right| p\) and \(q\) are maximum and minimum value of \(D\) respectively then, the value of \(2 p+3 q\) is ____________ .
- A 16
- B 6
- C 14
- D 8
Answer & Solution
Correct Answer
(C) 14
Step-by-step Solution
Detailed explanation
\(D = 1(1 + \cos^2 \theta) + \cos \theta(\cos \theta + \cos \theta) - 1(\cos^2 \theta - 1)\) \(D = 1 + \cos^2 \theta + 2\cos^2 \theta - \cos^2 \theta + 1\)
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