Answer:
y = (x +
)² -

Explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
To obtain this form use the method of completing the square.
Given
y = x² + 3x + 1
add/ subtract ( half the coefficient of the x- term )² to x² + 3x
y = x² + 2(
)x +
-
+ 1
= (x +
)² -
