Question

Where is the vertex of the parabola? y = x2 + 2x – 3 a. above the x-axis b. below the x-axis c. on the x-axis d. on the y-axis

Answer 1

The equation for this parabola is in standard form: y = ax² + bx + c
a, b, and c stand for coefficients. In standard form, in order to find the x-coordinate of the vertex of the parabola, plug in the associated variables in the expression "-(b/2a)". 
Plugging in the values for a and b gives:
-(2/2*1)
-(2/2)
-1
x = -1
From here, by plugging this value of x in for a corresponding answer, one can find the location of the vertex.
y = (-1)² + 2(-1) - 3
y = 1 + -2 - 3
y = 1 - 2 - 3
y = -4
Vertex of the parabola: (-1,-4)
Because y is negative, the answer is B) below the x-axis.