Q116 / 180 · KCET 2020 · Mathematics
If $f(x)=\left|\begin{array}{ccc}x^{3}-x & a+x & b+x \\ x-a & x^{2}-x & c+x \\ x-b & x-c & 0\end{array}\right|$, then
- A$f(\mathrm{l})=0$
- B$f(2)=0$
- Correct answerC$f(0)=0$
- D$f(-1)=0$
Solution
We have,
$\begin{aligned}
f(x) &=\left|\begin{array}{ccc}
x^{3}-x & a+x & b+x \\
x-a & x^{2}-x & c+x \\
x-b & x-c & 0
\end{array}\right| \\
f(0) &=\left|\begin{array}{ccc}
0 & a & b \\
-a & 0 & c \\
-b & -c & 0
\end{array}\right| \\
f(0)=0 &
\end{aligned}$
$f(0)$ is skew symmetric matrix of order $3 .$
Hence, the correct answer is option: 'C'.