The number of values of a for which the pair of lines represented by 3 a x 2 + 5 x y + a 2 - 2 y 2 = 0 are…

The number of values of a for which the pair of lines represented by 3ax2+5xy+a2-2y2=0 are at right angles to each other, is
  1. 2
  2. 1
  3. infinitely many
  4. 0

Solution

The pair of the lines represented by the given equation will be perpendicular to each other, when

Coefficient of x2+ coefficient of y2=0

3a+a2-2=0

On solving the above quadratic equation,

a=-3±172

There are two values.

Asked in: AP EAMCET 2019 (21 Apr Shift 2)

Practice more Pair of Lines questions on Aicharya