Q4 / 124 · NTA Abhyas (JEE Main) 2020 · Mathematics · Determinants

Let a, x, y, z be real numbers satisfying the equations 
ax+ay=z
x+ay=z
x+ay=az, where
x, y, z are not all zero, then the number of the possible values of a is

Correct answer: 2

Solution

As x, y, z are not all zero, thus the system has a non-trivial solution.
Thus, D=0
⇒aa-11a-11a-a=0
⇒aa2-a-aa-1+1a-a=0 or a3-a2-a2+a=0
⇒aa2-2a+1=0
⇒a=0, 1

Hence, the correct answer is 2.

More Determinants Questions