CUET · MATHS · PYQ PAPER 2023
Sum of the minor and the cofactor of the element 6 in the determinant \(\left|\begin{array}{lll}2 & 3 & 1 \\ 4 & 5 & 6 \\ 7 & 8 & 9\end{array}\right|\) is :
- A -5
- B -10
- C 10
- D 0
Answer & Solution
Correct Answer
(D) 0
Step-by-step Solution
Detailed explanation
\(M_{23} = \left| \begin{array}{cc} 2 & 3 \\ 7 & 8 \end{array} \right| = (2 \times 8) - (3 \times 7) = 16 - 21 = -5\) \(C_{23} = (-1)^{2+3} M_{23} = (-1)^5 (-5) = -1(-5) = 5\) \(M_{23} + C_{23} = -5 + 5 = 0\)
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
- Match (List I) with (List II)
Choose the correct answer from the options given below:(List I) (List II) A. For any vector \(\vec{a}, \vec{a} \times \vec{a}\) \(I\). \(|\vec{a}|^2\) B. For any vector \(\vec{a}, \vec{a} \cdot \vec{a}\) \(II.\) \(0\) C. If either \(\vec{a}=\overrightarrow{0}\) or \(\vec{b}=\overrightarrow{0}\), then \(\vec{a} \cdot \vec{b}\) is \(III.\) \(|\vec{a}||\vec{b}|\) D. If the angle between \(\vec{a}\) and \(\vec{b}\) is \(\theta=0\), then \(\vec{a} \cdot \vec{b}\) is \(IV.\) \(\overrightarrow{0}\) CUET 2023 Medium - For the LPP :
Maximise \(z=4 x+y\)
subject to constraints
\(x+y \leq 50, \quad 3 x+y \leq 90, \quad x \geq 0, y \geq 0\) the maximum value of \(z\) is :CUET 2023 Hard - If an asset costs Rs. 50,000 with an estimated useful life of 6 years and a scrap value of Rs. 5000. Then by using a linear depreciation method, the annual depreciation of the asset will be:CUET 2025 Easy
- If \(\int \frac{2 x}{x^2+3 x+2} d x=m \log |x+2|+n \log |x+1|+C\), then the values of m and n are:CUET 2023 Medium
- For the function \(f(x)=x^{1 / x}, x>0\), which of the following are correct?
(A) \(x=0\) is the only point where extremum may occur.
(B) The given function is maximum at \(x=e\).
(C) The function has no extreme value for \(x>0\).
(D) The maximum value of the function \(f(x)\) is \(e^{1 / e}\)
Choose the correct answer from the options given below :CUET 2025 Easy - If \(A=\left[\begin{array}{ll}x & 3 \\ 2 & y\end{array}\right], \quad B=\left[\begin{array}{cc}2 y & 1 \\ 3 & x\end{array}\right]\) and \(A+2 B=\left[\begin{array}{cc}6 & 5 \\ 8 & -2\end{array}\right]\), then the value of \((x, y)\) is:CUET 2023 Medium
More PYQs from CUET
- In a reaction \(2A \to B\), the concentration of A decreases from 0.64 M to 0.22 M in 5 minutes. What is the rate of reaction (in \(M s^{-1}\)) during this interval ?CUET 2023 Medium
- Two point charges of \( 1 \times 10^{-6} \, C \) and \( 4 \times 10^{-6} \, C \) are placed at a certain distance away from each other. The resultant electric field intensity is zero at a distance of 15 cm from the charge \( 1 \times 10^{-6} \, C \). The distance between the two point charges will be :CUET 2025 Medium
- Answer the questions on the basis of passage given below :
As aldehydes ketones possess the carbonyl functional group, they show similar reactions. They exhibit nucleophilic addition reactions, reduction, oxidations, reactions due to alpha-Hydrogen atom, and many other reactions, like Cannizzaro reaction to electrophilic substitution reactions (in case of aromatic aldehydes ketones).
These reactions help in the preparation of a number of important compounds, like acetic acid, vinyl acetate, polymers and in perfume and dye industries.
Nucleophilic addition reactions form cyanohydrins, acetals, alcohols and N -substituted derivatives like imine, oxime, semicarbazone, phenylhydrazone Schiff's base. Reactions due to alpha-hydrogen atoms help in formation of aldols and alpha, beta-unsaturated aldehydes ketones.
Which of the following combinations of Grignard's reagent and carbonyl compound can give \(C _6 H _5- C ( OH )\left( CH _3\right)- CH \left( CH _3\right)_2\)
A. \(C _6 H _5 CH _2 MgBr +\left( CH _3\right)_2 CH - CHO\)
B. \(C _6 H _5 MgBr + CH _3- CO - CH \left( CH _3\right)_2\)
C. \(CH _3 MgBr + C _6 H _5- CO - CH \left( CH _3\right)_2\)
D. \(C _6 H _5- CO - CH _3+\left( CH _3\right)_2 CHMgBr\)
E. \(C _6 H _5 CH ( MgBr ) CH _3+\left( CH _3\right)_2 CO\)
Choose the correct answer from the option given below :CUET 2023 Easy - Arrange the given organisms involved in an ecosystem in correct sequence from lower to higher order.
(A) Fish
(B) Phytoplankton
(C) Man
(D) Zooplankton
Choose the correct answer from the options given below:CUET 2025 Hard - The integral value of \(k\) for which the system of linear equations
\(\begin{array}{l}k x+y+2 z=0 \\k y=x-3 z \\2 x+y+k z=0\end{array}\)
has a non-zero solution is :CUET 2025 Medium - With reference to sampling, which of the following are correct?
(A) Simple random sampling is probability sampling
(B) Snow-ball sampling is non-probability sampling
(C) Stratified sampling is probability sampling
(D) Cluster sampling is non-probability sampling
Choose the correct answer from the options given below:CUET 2025 Easy