Question
Write the value of the determinant $\begin{vmatrix}\text{x}+\text{y}&\text{y}+\text{z}&\text{z}+\text{x}\\\text{z}&\text{x}&\text{y}\\-3&-3&-3 \end{vmatrix}$

Answer

$\begin{vmatrix}\text{x}+\text{y}&\text{y}+\text{z}&\text{z}+\text{x}\\\text{z}&\text{x}&\text{y}\\-3&-3&-3 \end{vmatrix}$
$=\begin{vmatrix}\text{x}+\text{y}+\text{z}&\text{x}+\text{y}+\text{z}&\text{z}+\text{x}+\text{y}\\\text{z}&\text{x}&\text{y}\\-3&-3&-3 \end{vmatrix}$ [Applying $R_1 → R_1 + R_2$]
$=(\text{x}+\text{y}+\text{z})\begin{vmatrix}1&1&1\\\text{z}&\text{x}&\text{y}\\-3&-3&-3 \end{vmatrix}$ [Taking (x + y + z) common from $R_1$]
$=(\text{x}+\text{y}+\text{z})\begin{vmatrix}1&1&1\\\text{z}&\text{x}&\text{y}\\0&0&0 \end{vmatrix}$
$=0$ [Expanding along the last row]
Hence, the value of the determinant $\begin{vmatrix}\text{x}+\text{y}&\text{y}+\text{z}&\text{z}+\text{x}\\\text{z}&\text{x}&\text{y}\\-3&-3&-3 \end{vmatrix}$ is 0

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 be the set of all human beings in a town at a particular time. Determine whether the following relations are reflexive, symmetric and transitive:
R = {(x, y): x and y live in the same locality}
A bag consists of 10 balls each marked with one of the digits 0 to 9. If four balls are drawn successively with replacement from the bag, what is the probability that none is marked with the digit 0?
Three machines $\mathrm{E}_1, \mathrm{E}_2, \mathrm{E}_3$ in a certain factory produce $50 \%, 25 \%$ and $25 \%$, respectively, of the total daily output of electric bulbs. It is known that $4 \%$ of the tubes produced one each of the machines $\mathrm{E}_1$ and $\mathrm{E}_2$ are defective, and that $5 \%$ of those produced on $E_3$ are defective. If one tube is picked up at random from a day's production, then calculate the probability that it is defective.
Let A = [-1, 1]. Then, discuss whether the following functions from A to itself are one-one, onto or bijective:
g(x) = |x|
From a pack of 52 cards, 4 are drawn one by one without replacement. Find the probability that all are aces (or kings).
For the binary operation $\times _7$ on the set $S =\{1, 2, 3, 4, 5, 6\},$ compute $3^{−1} \times _7 4.$
Write the direction cosines of the line $\frac{\text{x}-2}{2}=\frac{2\text{y}-5}{-3},\text{z}=2.$
On the set Z of integers, if the binary operation * is defined by a * b = a + b + 2, then find the identity element.
Find the probability distribution of
number of heads in two tosses of a coin.
A bag contains $6$ red and $8$ black balls and another bag contains $8$ red and $6$ black balls. A ball is drawn from the first bag and without noticing its colour is put in the second bag. A ball is drawn from the second bag. Find the probability that the ball drawn is red in colour.