Generally, we can use formula to find the vertex and symmetry axis of parabola y = ax ^ 2 + BX + C (a ≠ 0). Y = ax ^ 2 + BX + C = a [x + (B / 2a)] ^ 2+ Generally, we can find the vertex and symmetry axis of parabola y = ax ^ 2 + BX + C (a ≠ 0) y=ax^2 + bx + c =a[x+(b/2a)]^2 + (4ac-b^2)/4a, y=ax^2 + bx + c It should not be converted to (x + B / 2a) ^ 2 = B ^ 2-4ac / 4A ^ 2. How can it be converted to the above form?

Generally, we can use formula to find the vertex and symmetry axis of parabola y = ax ^ 2 + BX + C (a ≠ 0). Y = ax ^ 2 + BX + C = a [x + (B / 2a)] ^ 2+ Generally, we can find the vertex and symmetry axis of parabola y = ax ^ 2 + BX + C (a ≠ 0) y=ax^2 + bx + c =a[x+(b/2a)]^2 + (4ac-b^2)/4a, y=ax^2 + bx + c It should not be converted to (x + B / 2a) ^ 2 = B ^ 2-4ac / 4A ^ 2. How can it be converted to the above form?

The formula (x + B / 2a) ^ 2 = B ^ 2-4ac / 4A ^ 2 written by you has default that f (x) is equal to zero, but the original formula y = ax ^ 2 + BX + C is a function relation, which is not equal to a fixed value, or simply speaking, it is not an equation. Your understanding of function is wrong

Given that a ＜ 0. B ＞ 0. C ＞ 0. What quadrant is the vertex of the parabola y = ax ∧ + BX + C?

Should be y = ax ^ 2 + BX + C? Vertex coordinates (- 2A / B, C-B ^ 2 / 4A) because Ao, so - 2A / b > 0, because C > 0, so C-B ^ 2 / 4A > O, so vertex coordinates in the first quadrant