Question

What will be the condition for ($a^2$ - 9)$x^2$ + bx + c = 0 to be a quadratic equation?

Answer 1

For any quadratic equation of standard form a$x^2$ + bx + c = 0 the condition is a,b,c should be real number and a≠0. So considering the same here $a^2$ - 9 should not be zero.

$a^2$ - 9 $\ne$0

$a^2$ $\ne$ 9

a$\ne$3,-3

So for above equation to be of degree 2, the coefficient of $x^2$ should not be equal to zero, i.e. a≠3 and also a≠ -3.