Question

In the definition of the discriminant for \[ax^{2} + bx + c = 0\], which condition must be satisfied by the coefficient \[a\]?

Options

• \[a = 1\]

• \[a \neq 0\]

• \[a < 0\]

• \[a > 0\]

Answer 1

The equation \[ax^{2} + bx + c = 0\] is quadratic only when \[a \neq 0\]. If \[a = 0\], the \[ax^{2}\] term vanishes and the equation is no longer quadratic, so the discriminant \[D = b^{2} - 4ac\] is defined under the condition \[a \neq 0\].