The graph of which equation is shown below?

y = −x2 + 2x − 3

y = −x2 − 2x − 3

y = x2 + 2x − 3

y = x2 − 2x − 3

Question

The graph of which equation is shown below?

 y = −x2 + 2x − 3

 y = −x2 − 2x − 3

 y = x2 + 2x − 3

 y = x2 − 2x − 3

anonymous · Answer

attachment

anonymous · Answer

The parabola is positive. THis means the x^2 term has to be positive. Then, the vertex is at  (-1, -4). THe formula to find the x-value of the vertex is -b/2a. THen, just plug this value in for x and solve for y. If it matches up to the vertex, then it works.

anonymous · Answer

but what equation do i make? -1/2(-4)?

anonymous · Answer

Alright.$$-1 = -\frac{b}{2(a)}$$
$$-1 = -\frac{b}{2(1)}$$
$$-1 = -\frac{b}{2}$$
$$2 = b$$
Therefore, the answer is  y = x^2 + 2x − 3 because b = 2 here.