If the points (2, 1), (-1, 4) and (a, 3) are collinear then the value/(s) of a is/(are):
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) - 0
given points → collinear
$Δ=\begin{vmatrix}2&1&1\\-1&4&1\\a&3&1\end{vmatrix}$
$⇒R_2→R_2-R_1,R_3→R_3-R_1$
$\begin{vmatrix}2&1&1\\-3&3&0\\a-2&2&0\end{vmatrix}=0$
$⇒-6-3a+6=0$
$⇒a=0$