WBJEE · Maths · Matrices
Let \(\mathrm{A}=\left(\begin{array}{ccc}12 & 24 & 5 \\ \mathrm{x} & 6 & 2 \\ -1 & -2 & 3\end{array}\right) .\) The value of \(\mathrm{x}\) for which the matrix \(\mathrm{A}\) is not invertible is
- A 6
- B 12
- C 3
- D 2
Answer & Solution
Correct Answer
(C) 3
Step-by-step Solution
Detailed explanation
Hint: If matrix is not invertible \(\Rightarrow|\mathrm{A}|=0\) \(\therefore|\mathrm{A}|=\left|\begin{array}{ccc}12 & 24 & 5 \\ \mathrm{x} & 6 & 2 \\ -1 & -2 & 3\end{array}\right|=0 \Rightarrow \mathrm{x}=3\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Maths
- Let the eccentricity of the hyperbola \(\frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}=1\) be reciprocal to that of the ellipse \(x^{2}+9 y^{2}=9,\) then the ratio \(a^{2}: b^{2}\) equalsWBJEE 2018 Easy
- If in a \(\triangle A B C, A D, B E\) and \(C F\) are the altitudes and \(R\) is the circumradius, then the radius of the circumcircle of \(\Delta D E F\) isWBJEE 2016 Medium
- If the relation between the direction ratios of two lines in \(\mathbb{R}^3\) are given by \(l+m+n=0,2 / m+2 m n-l n=0\) then the angle between the lines is ( \(I, m\), \(n\) have their usual meaning)WBJEE 2024 Easy
- The value of \(\cos ^{2} 75^{\circ}+\cos ^{2} 45^{\circ}+\cos ^{2} 15^{\circ}\) \(-\cos ^{2} 30^{\circ}-\cos ^{2} 60^{\circ}\) isWBJEE 2013 Easy
- If \(A\) and \(B\) square matrices of the same order and \(A B=3 I\), then \(A^{-1}\) is equal toWBJEE 2009 Easy
- The value of \((1+\cos \pi / 6)(1+\cos \pi / 3)(1+\cos 2 \pi / 3)(1+\cos 7 \pi / 6)\) isWBJEE 2009 Easy
More PYQs from WBJEE
- If \(\vec{\alpha}\) is a unit vector, \(\vec{\beta}=\hat{\mathrm{i}}+\hat{\mathrm{j}}-\hat{\mathrm{k}}, \vec{\gamma}=\hat{\mathrm{i}}+\hat{\mathrm{k}}\), then the maximum value of \([\vec{\alpha} \vec{\beta} \vec{\gamma}]\) isWBJEE 2022 Easy
- A junction diode has a resistance of \(25 \Omega\) when forward biased and \(2500 \Omega\) when reverse biased. The current in the diode, for the arrangement shown will be
WBJEE 2009 Easy - Mixing of two different ideal gases under isothermal reversible condition will lead toWBJEE 2013 Easy
- Let \(A, B\) be two distinct points on the parabola \(y^{2}=4 x\). If the axis of the parabola touches a circle of radius \(r\) having \(A B\) as diameter, the slope of the line \(A B\) isWBJEE 2018 Medium
- The following figure shows the variation of potential energy V(x) of a particle with distance x. The particle has
WBJEE 2024 Easy - The value of \(\lambda\) for which the curve \((7 x+5)^{2}+(7 y+3)^{2}=\lambda^{2}(4 x+3 y-24)^{2}\) representa a parabola isWBJEE 2014 Medium