Vertex form of a quadratic:
y = a (x - h)2 + k
In this case, the vertex is:
(h, k) = (-3, -1)
And, the point is:
(x, y) = (-4, 2)
To find "a", we substitute the vertex and the point in the formula:
2 = a ((-4) - (-3))2 + (-1)
2 = a (-4 + 3)2 - 1
2 = a (-1)2 -1
2 = a (1) - 1
2 = a - 1
2 + 1 = a
a = 3
Equation for the quadratic in Vertex Form:
y = 3 (x - (-3))2 + (-1)
y = 3 (x + 3)2 - 1
To find the equation of the quadratic in Standard Form, we solve the vertex form:
y = 3 (x + 3)2 - 1
y = 3 (x2 + 6x + 9) - 1
y = 3x2 + 18x + 27 - 1
y = 3x2 + 18x + 26
Equation of the quadratic:
Vertex form: y = 3 (x + 3)2 - 1
Standard form: y = 3x2 + 18x + 26