To find the y-intercept, set x equal to 0. 0^2= 0 2*0 = 0 and you are left with y=-3
(0,-3) is the y-intercept.
Yo find the Vertex: x coordinate of vertex is -b/2a = -2 / 2 = -1
y coordinate of the vertex = (-1)^2+2(-1)-3=1-2-3 = -4
vertex is (-1,-4)
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You can use the quadratic equation with the following values to find the zeros:
a=1, b=2 and c=-3