Question 12488
You had the right idea for finding the vertex of the parabola but got the wrong answer.

{{{y = x^2 + 2x - 3}}} Here: a = 1, b = 2, and c = -3, so:

{{{(-b)/2a = -2/2}}} = -1 So the x-coordinate of the vertex is -1.  To find the y-coordinate, substitute -1 for x in the equation and solve for y.

{{{y = (-1)^2 + 2(-1) - 3}}}
{{{y = 1 - 2 - 3}}}
{{{y = -4}}} The y-coordinate is -4.

The vertex is at (-1, -4)

The x-intercepts are found by setting y = 0 and solving for x (there will be two of them).

{{{0 = x^2 + 2x - 3}}} Solve by factoring.
{{{(x - 1)(x + 3) = 0}}}
{{{x-1 = 0}}} and {{{x + 3 = 0}}}

{{{x = 1}}} and {{{x = -3}}}

The y-intercept is found by setting x = 0 and solving for y.

{{{y = 0^2 + 2(0) - 3}}}
{{{y = -3}}}

Let's see what the graph look like:

{{{graph(300,200,-6,6,-6,6,x^2+2x-3)}}}