ExamBro
ExamBro
JEE Mains · Maths · STD 12 - 3 and 4 . metrices and determinant

निम्न कथनों में से:
I: यदि \( \begin{vmatrix} 1 & \cos \alpha & \cos \beta \\ \cos \alpha & 1 & \cos \gamma \\ \cos \beta & \cos \gamma & 1 \end{vmatrix} = \begin{vmatrix} 0 & \cos \alpha & \cos \beta \\ \cos \alpha & 0 & \cos \gamma \\ \cos \beta & \cos \gamma & 0 \end{vmatrix} \), तो \( \cos^{2}\alpha+\cos^{2}\beta+\cos^{2}\gamma=\frac{3}{2} \)
II: यदि \( \begin{vmatrix} x^{2}+x & x+1 & x-2 \\ 2x^{2}+3x-1 & 3x & 3x-3 \\ x^{2}+2x+3 & 2x-1 & 2x-1 \end{vmatrix} = px+q \), तो \( p^{2}=196q^{2} \),

  1. A दोनों असत्य हैं
  2. B केवल II सत्य है
  3. C दोनों सत्य हैं
  4. D केवल I सत्य है
Verified Solution

Answer & Solution

Correct Answer

(A) दोनों असत्य हैं

Step-by-step Solution

Detailed explanation

Let \(\cos \alpha= x\) \(\cos \beta=y\) \(\cos \gamma= z\) \(\left|\begin{array}{lll}0 & x & y \\ x & 0 & z \\ y & z & 0\end{array}\right|=\left|\begin{array}{lll}1 & x & y \\ x & 1 & z \\ y & z & 1\end{array}\right|\) Expending both sides, we get \(x^2+y^2+z^2=1\) i.e.…
Same subject
Explore more questions on app
From JEE Mains
Explore more questions on app