When does the image of quadratic function pass through the origin?

When does the image of quadratic function pass through the origin?

1. In the general form of quadratic function ax & # 178; + BX + C (a ≠ 0), C can shift the function image up and down,
When the symmetry axis (- B / 2a) is 0 and C = 0, the function image passes through the origin
2. In the form of a (X-H) ² + K, when the vertex (h, K) = (0,0), the function image passes through the origin