1. LearninDaMath

300
A quadratic equation has the form y = ax^2 + bx + c. However, if c = 0, then y = ax^2 + bx. Is it still called a quadratic equation? And if b = 0 so that y = ax^2, is it still given the title of quadratic equation?

I would guess yes since it still has a power of 2 and is a parabola. Is this correct?

Staff: Mentor

What you're showing is a quadratic function. A quadratic equation in standard form looks like this:
ax2 + bx + c = 0
ax2 + bx = 0 is still a quadratic equation. The only restriction is that a $\neq$ 0.