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Saturday, 31 October

JEE Main 2022 · MathsMultiple choiceSingle correctMediumMulti-step

JEE Main 29 June 2022, Shift 1, Maths Q10

Question 10 of 90 in this shift, Maths question 10 of 30, Section A.

Let A=[aij]A = [a_{ij}] be a square matrix of order 3 such that aij=2j−ia_{ij} = 2^{j-i}, for all i,j=1,2,3i, j = 1, 2, 3. Then, the matrix A2+A3+…+A10A^2 + A^3 + \ldots + A^{10} is equal to :
  1. (1)(310−32)A\left(\frac{3^{10} - 3}{2}\right)AOfficial answer
  2. (2)(310−12)A\left(\frac{3^{10} - 1}{2}\right)A
  3. (3)(310+12)A\left(\frac{3^{10} + 1}{2}\right)A
  4. (4)(310+32)A\left(\frac{3^{10} + 3}{2}\right)A

Official answer

Option 1

NTA final key (2022 Session 1).

Chapter
Matrices

Same idea in other shifts

Asked 21× in all
  1. 4 Apr 2025, Shift 2 · Q4Let the matrix A=[100101010]A=\begin{bmatrix}1&0&0\\1&0&1\\0&1&0\end{bmatrix} satisfy An=An−2+A2−IA^n=A^{n-2}+A^2-I for n≥3n\ge 3. Then the sum of all the…HardSingle correct
  2. 4 Apr 2024, Shift 2 · Q3Let A=[1201]A=\begin{bmatrix}1&2\\0&1\end{bmatrix} and B=I+adj(A)+(adj A)2+…+(adj A)10B=I+\mathrm{adj}(A)+(\mathrm{adj}\,A)^2+\ldots+(\mathrm{adj}\,A)^{10}. Then, the sum of…MediumSingle correct
  3. 8 Apr 2024, Shift 1 · Q22Let A=[2−111]A=\begin{bmatrix}2&-1\\1&1\end{bmatrix}. If the sum of the diagonal elements of A13A^{13} is 3n3^n, then nn is equal to ____________.MediumNumerical value
  4. 6 Apr 2023, Shift 2 · Q4Let PP be a square matrix such that P2=I−PP^2=I-P. For α,β,γ,δ∈N\alpha,\beta,\gamma,\delta\in\mathbb{N}, if Pα+Pβ=γI−29PP^\alpha+P^\beta=\gamma I-29P and…HardSingle correct
  5. 8 Apr 2023, Shift 1 · Q5Let P=[3212−1232]P=\begin{bmatrix}\frac{\sqrt{3}}{2}&\frac{1}{2}\\-\frac{1}{2}&\frac{\sqrt{3}}{2}\end{bmatrix},…HardSingle correct
  6. 11 Apr 2023, Shift 1 · Q29Let A=[012a031c0]A = \begin{bmatrix} 0 & 1 & 2 \\ a & 0 & 3 \\ 1 & c & 0 \end{bmatrix}, where a,c∈Ra, c \in \mathbb{R}. If A3=AA^3 = A and the positive…HardNumerical value
  7. 12 Apr 2023, Shift 1 · Q3Let A=[115101]A=\begin{bmatrix}1&\frac{1}{51}\\0&1\end{bmatrix}. If…HardSingle correct
  8. 25 Jul 2022, Shift 1 · Q21Let A=(2−1−110−11−10)A=\begin{pmatrix}2&-1&-1\\1&0&-1\\1&-1&0\end{pmatrix} and B=A−IB=A-I. If ω=3 i−12\omega=\frac{\sqrt3\,i-1}{2}, then the number of elements in…HardNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.