If $f(x) = \begin{vmatrix} 0 & x-a & x-b \\ x+a & 0 & x-c \\ x+b & x+c & 0 \end{vmatrix}$, then
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → $f(0) = 0$ ##
We have,
$f(x) = \begin{vmatrix} 0 & x-a & x-b \\ x+a & 0 & x-c \\ x+b & x+c & 0 \end{vmatrix} \quad \dots(i)$
On substituting $x = a$ in Eq. (i) we get
$\Rightarrow f(a) = \begin{vmatrix} 0 & 0 & a-b \\ 2a & 0 & a-c \\ a+b & a+c & 0 \end{vmatrix}$
On expanding along $R_1$, we get
$= [(a-b)(2a \cdot (a+c))] \neq 0$
On substituting $x = b$ in Eq. (i) we get
$∴f(b) = \begin{vmatrix} 0 & b-a & 0 \\ b+a & 0 & b-c \\ 2b & b+c & 0 \end{vmatrix}$
On expanding along $R_1$, we get
$= -(b-a)[-2b(b-c)]$
$= 2b(b-a)(b-c) \neq 0$
On substituting $x = 0$ in Eq. (i) we get
$∴f(0) = \begin{vmatrix} 0 & -a & -b \\ a & 0 & -c \\ b & c & 0 \end{vmatrix}$
On expanding along $R_1$, we get
$= a(bc) - b(ac)$
$= abc - abc = 0$