Download App

3 and 4 . determinant and metrices — Maths STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceMaths3 and 4 . determinant and metrices1 Mark
MCQ
If $A = \left[ {\begin{array}{*{20}{c}}1&0&0\\0&1&0\\a&b&{ - 1}\end{array}} \right]$, then  ${A^2} = $
  • ✓
    Unit matrix
  • B
    Null matrix
  • C
    $A$
  • D
    $-A$
✓

Answer

Correct option: A.
Unit matrix
a
(a) ${A^2} = A.\,A = \left[ {\begin{array}{*{20}{c}}1&0&0\\0&1&0\\a&b&{ - 1}\end{array}} \right]\,\left[ {\begin{array}{*{20}{c}}1&0&0\\0&1&0\\a&b&{ - 1}\end{array}} \right] = \left[ {\begin{array}{*{20}{c}}1&0&0\\0&1&0\\0&0&1\end{array}} \right] = I$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 3 and 4 . determinant and metrices→3 and 4 . determinant and metrices — all question types→Maths STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

If $\text{f}(\text{x})=\sqrt{\text{x}^2+6\text{x}+9},$ then f'(x) is equal to:
  1. 1 for x < -3
  2. -1 for x < -3
  3. 1 for all $\text{x}\in\text{R}$
  4. None of these.
→
The positive value of the determinant of the matrix $A$, whose $A d j(A d j(A))=\left(\begin{array}{ccc}14 & 28 & -14 \\ -14 & 14 & 28 \\ 28 & -14 & 14\end{array}\right)$, is
→
The area of the region given by $A=\left\{(x, y): x^{2} \leq y \leq \min \{x+2,4-3 x\}\right\}$ is.
→
 Solve system of linear equations, using matrix method. $x-y+2 z=7$ ;  $3 x+4 y-5 z=-5$ ; $2 x-y+3 z=12$
→
The region represented by the inequation system x, y ≥ 0, y ≤ 6, x + y ≤ 3 is:
  1. unbounded in first quadrant
  2. unbounded in first and second quadrants
  3. bounded in first quadrant
  4. none of these
→
Let $f: \mathbb{R} \rightarrow \mathbb{R}, \quad g: \mathbb{R} \rightarrow \mathbb{R}$ and $h: \mathbb{R} \rightarrow \mathbb{R}$ be differentiable functions such that $f(x)=x^3+3 x+2, g(f(x))=x$ and $h(g(g(x)))=x$ for all $x \in \mathbb{R}$. Then

($A$) $g^{\prime}(2)=\frac{1}{15}$  ($B$) $h^{\prime}(1)=666$  ($C$) $h(0)=16$   ($D$) $h(g(3))=36$

→
Let $X$ be a random variable having binomial distribution $B (7, p )$. If $P ( X =3)=5 P ( X =4)$, then the sum of the mean and the variance of $X$ is
→
The vector component of $\vec{\text{b}}$ perpendicular to $\vec{\text{a}}$ is:
  1. $\big(\vec{\text{b}}.\vec{\text{c}}\big)\vec{\text{a}}$
  2. $\frac{\vec{\text{a}}\times\big(\vec{\text{b}}\times\vec{\text{a}}\big)}{|\vec{\text{a}}|^2}$
  3. $\vec{\text{a}}\times\big(\vec{\text{b}}\times\vec{\text{a}}\big)$
  4. None of these
→
Which of the following functions form Z to itself are bijections?
  1. f(x) = x3
  2. f(x) = x + 2
  3. f(x) = 2x + 1
  4. f(x) = x2 + x
→
The angle between the lines $2 x=3 y=-z$ and $6 x=-y=-4 z$ is
→