JEE Mains · Maths · STD 12 - 3 and 4 . metrices and determinant
Let \(\mathrm{A}\) and \(\mathrm{B}\) be two square matrices of order \(3\) such that \(|A|=3\) and \(|B|=2\). Then \(\left|\mathrm{A}^{\mathrm{T}} \mathrm{A}(\operatorname{adj}(2 \mathrm{~A}))^{-1}(\operatorname{adj}(4 \mathrm{~B}))(\operatorname{adj}(\mathrm{AB}))^{-1} \mathrm{AA}^{\mathrm{T}}\right|\) is equal to :
- A \(64\)
- B \(81\)
- C \(32\)
- D \(108\)
Answer & Solution
Correct Answer
(A) \(64\)
Step-by-step Solution
Detailed explanation
\( |\mathrm{A}|=3,|\mathrm{~B}|=2 \) \( \left|\mathrm{~A}^{\mathrm{T}} \mathrm{A}(\operatorname{adj}(2 \mathrm{~A}))^{-1}(\operatorname{adj}(4 \mathrm{~B}))(\operatorname{adj}(\mathrm{AB}))^{-1} \mathrm{AA}^{\mathrm{T}}\right| \)…
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
- For a statistical data \(\mathrm{x}_1, \mathrm{x}_2, \ldots, \mathrm{x}_{10}\) of 10 values, a student obtained the mean as 5.5 and \(\sum_{i=1}^{10} x_i^2=371\). He later found that he had noted two values in the data incorrectly as 4 and 5 , instead of the correct values 6 and 8 , respectively. The variance of the corrected data isJEE Mains 2025 Medium
- The locus of the foot of perpendicular drawn from the centre of the ellipse \({x^2} + 3{y^2} = 6\) on any tangent to it isJEE Mains 2014 Hard
- Let \(S=\{4,6,9\}\) and \(T=\{9,10,11, \ldots, 1000\}\). If \(A=\left\{a_{1}+a_{2}+\ldots+a_{k}: k \in N, a_{1}, a_{2}, a_{3}, \ldots, a_{k} \in S\right\}\) then the sum of all the elements in the set \(T - A\) is equal to \(......\)JEE Mains 2022 Hard
- Let \(P_n=\alpha^n+\beta^n, n \in \mathbf{N}\). If \(P_{10}=123, P_9=76\), \(P_8=47\) and \(P_1=1\), then the quadratic equation having roots \(\frac{1}{\alpha}\) and \(\frac{1}{\beta}\) is :JEE Mains 2025 Medium
- Different \(A.P.\)'s are constructed with the first term \(100\),the last term \(199\),And integral common differences. The sum of the common differences of all such, \(A.P\)'s having at least \(3\) terms and at most \(33\) terms is.JEE Mains 2022 Hard
- A group of \(40\) students appeared in an examination of \(3\) subjects - Mathematics, Physics Chemistry. It was found that all students passed in at least one of the subjects, \(20\) students passed in Mathematics, \(25\) students passed in Physics, \(16\) students passed in Chemistry, at most \(11\) students passed in both Mathematics and Physics, at most \(15\) students passed in both Physics and Chemistry, at most \(15\) students passed in both Mathematics and Chemistry. The maximum number of students passed in all the three subjects is ........... .JEE Mains 2024 Hard
More PYQs from JEE Mains
- In a bombing attack, there is \(50 \%\) chance that a bomb will hit the target. At least two independent hits are required to destroy the target completely. Then the minimum number of bombs, that must be dropped to ensure that there is at least \(99 \%\) chance of completely destroying the target, isJEE Mains 2020 Medium
- Let the set \(\mathrm{S}=\{2,4,8,16, \ldots . .512\}\) be partitioned into \(3\) sets \(A, B, C\) with equal number of elements such that \(\mathrm{A} \cup \mathrm{B} \cup \mathrm{C}=\mathrm{S}\) and \(\mathrm{A} \cap \mathrm{B}=\mathrm{B} \cap \mathrm{C}=\mathrm{A} \cap \mathrm{C}=\phi\). The maximum number of such possible partitions of \(S\) is equal to :JEE Mains 2024 Hard
- If \(y\, = mx + c\) is the normal at a point on the parabola \(y^2\, = 8x\) whose focal distance is \(8\, units\), then \(\left| c \right|\) is equal toJEE Mains 2017 Hard
- Let f, g: \(R \rightarrow R\) be functions defined by \(f ( x )=\left\{\begin{array}{ll}{[ x ]} & , \quad x < 0 \\ |1- x | & , \quad x \geq 0\end{array}\right.\) and \(g(x)=\left\{\begin{array}{ll}e^{x}-x & , x < 0 \\ (x-1)^{2}-1 & , \quad x \geq 0\end{array}\right.\) where \([ x ]\) denote the greatest integer less than or equal to \(x\). Then, the function fog is discontinuous at exactlyJEE Mains 2022 Hard
- The number of distinct real roots of the equation \(|\mathrm{x}+1||\mathrm{x}+3|-4|\mathrm{x}+2|+5=0\), is ...........JEE Mains 2024 Hard
- Given three points \(P, Q, R\) with \(P(5, 3)\) and \(R\) lies on the \(x-\) axis. If equation of \(RQ\) is \(x - 2y = 2\) and \(PQ\) is parallel to the \(x-\) axis, then the centroid of \(\Delta PQR\) lies on the lineJEE Mains 2014 Hard