MCQ
$\left| {\,\begin{array}{*{20}{c}}1&a&b\\{ - a}&1&c\\{ - b}&{ - c}&1\end{array}\,} \right| = $
  • $1 + {a^2} + {b^2} + {c^2}$
  • B
    $1 - {a^2} + {b^2} + {c^2}$
  • C
    $1 + {a^2} + {b^2} - {c^2}$
  • D
    $1 + {a^2} - {b^2} + {c^2}$

Answer

Correct option: A.
$1 + {a^2} + {b^2} + {c^2}$
a
(a) $\left| {\,\begin{array}{*{20}{c}}1&a&b\\{ - a}&1&c\\{ - b}&{ - c}&1\end{array}\,} \right| = 1\,(1 + {c^2}) - a( - a + bc) + b(ac + b)$

= $1 + {a^2} + {b^2} + {c^2}$.

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

Similar questions

Let $A = \{x : -1 \leq x \leq 1\}$ and $f : A \rightarrow A$ is a function defined by $f(x) = x |x|$ then $f$ is:
Choose the correct answer from the given four options. If $\begin{bmatrix}2\text{x}+\text{y}&4\text{x}\\5\text{x}-7&4\text{x}\end{bmatrix}=\begin{bmatrix}7&7\text{y}-13\\\text{y}&\text{x}+6\end{bmatrix},$ then the value of $x + y$ is :
Choose the correct answer from the given four options. Assume that in a family, each child is equally likely to be a boy or a girl. A family with three children is chosen at random. The probability that the eldest child is a girl given that the family has at least one girl is:
Let $P = \left[ {{a_{ij}}} \right]$ be $4 \times 4$ matrix. If $\left| P \right| =  - 2$ , then value of $\left| {\,\,adj\,\left( {3P} \right)} \right|$ ,is (where $|A|$ denotes determinant value of matrix $A$ )
Choose the correct answer from the given four options.Three persons, A, B and C, fire at a target in turn, starting with A. Their probability
of hitting the target are 0.4, 0.3 and 0.2 respectively. The probability of two hits
is:
$\int\text{e}^{\text{x}}\Big(\frac{1-\sin\text{x}}{1-\cos\text{x}}\Big)\text{dx}=$
In the interval (1, 2), function f(x) = 2|x - 1| + 3|x - 2| is:
The value of $\int_{\,0}^{\,\pi /2} {\frac{{{2^{\sin x}}}}{{{2^{\sin x}} + {2^{\cos x}}}}dx} $ is
The direction ratios of two lines $AB, AC$ are $1, -1, -1$ and $2, -1, 1.$ The direction ratios of the normal to the plane $\text{ABC}$ are:
$\int\text{x}^{\sin\text{x}}\Big(\frac{\sin\text{x}}{\text{x}}+\cos\text{x}\cdot\log\text{x}\Big)\text{dx}$ is equal to :