CUET · MATHS · PYQ PAPER 2025
If \(A\) is a square matrix such that \(A^2=A\) and \(I\) is the identity matrix of same order as \(A\), then the matrix \((2 I+A)^3-19 A-3 I\) is equal to
- A \(5 I\)
- B \(5 A\)
- C \(7 I\)
- D \(7 A\)
Answer & Solution
Correct Answer
(A) \(5 I\)
Step-by-step Solution
Detailed explanation
\((2 I+A)^2 = 4 I^2+4 IA+A^2 = 4I+4A+A = 4I+5A\) \((2 I+A)^3 = (2 I+A)(4 I+5 A) = 8 I^2+10 IA+4 AI+5 A^2 = 8 I+10 A+4 A+5 A = 8 I+19 A\) \((2 I+A)^3-19 A-3 I = (8 I+19 A)-19 A-3 I = 5 I\)
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 fixed radii of curvature of a lens, power is proportional to :CUET 2024 Medium
- For the function \(f(x)=2 x^3-3 x^2-12 x+5\), the difference of maximum and minimum value of \(f(x)\) isCUET 2025 Medium
- If A and B are square matrices of order 3 such that \(|A|=-1,|B|=3\) then \(|3 A B|\) is:CUET 2023 Hard
- The point on the curve \(y^2=x\), where the tangent makes an angle of \(\frac{\pi}{4}\) with x-axis is:CUET 2023 Hard
- In a game, A can give 36 points to B, A can give 42 point to C, B can give 10 points to C. How many points make the game?CUET 2025 Medium
- If the lines \(\frac{x+3}{k-5}=\frac{y-1}{1}=\frac{5-z}{-2 k-1}\) and \(\frac{x+2}{-1}=\frac{2-y}{-k}=\frac{z}{5}\) are perpendicular, then the value of \(k\) isCUET 2023 Medium
More PYQs from CUET
- If \(\left|\begin{array}{ccc}x-2 & 1 & 2 \\ 1 & 2 x & 1 \\ -1 & 1 & 1\end{array}\right|=3\) then the values of x are:CUET 2023 Medium
- Karyotype of an individual is 47, XXY. The individual is suffering from :CUET 2023 Hard
- Sexual stages of Plasmodium which develop in human RBCs are known as:-CUET 2023 Medium
- On passing ammonia gas through a solution of copper sulphate, a deep blue solution is obtained.
The deep blue colour of the solution is due to the formation of :CUET 2023 Easy - Four resistors of \( 8 \ \Omega \) each are connected in parallel, five such combinations are then connected in series. What is the total resistance?CUET 2023 Hard
- "Answer the question on basis of passage given below:
\(G = \frac{\kappa A}{l}\)=k (both \(A\) and \(l\) are unity in their appropriate units in m or cm)
Molar conductivity of a solution at a given concentration is the conductance of the volume \(V\) of solution containing one mole of electrolyte kept between two electrodes with area of cross section \(A\) and distance of unit length (\(l\)). Therefore,
\(\Lambda_m = \frac{\kappa A}{l}\)
Since \(l = 1\) and \(A = V\) (volume containing 1 mole of electrolyte),
\(\Lambda_m = \kappa V\)
If the length \(l\) in the column of an electrolytic cell is halved and its area of cross-section is tripled, then conductance (\(G\)) would become:"CUET 2023 Hard