Question

How do you graph `y = x² + 2x – 4`?

Answer 1

Graph y = x^2 + 2x - 4

Explanation:

To graph a parabola, find a few critical points:
Axis of symmetry --> `x = -b/2a = - 1`
Vertex --> `x = -b/2a = -1`
y = f(-1) = 1 - 2 - 4 = -5
y-intercept --> make x = 0 --> y = -4
x-intercept --> solve y = 0 --> `x^2 + 2x - 4 = 0.`
`D = d^2 = b^2 - 4ac = 4 + 16 = 20`-->`d = +- 2sqrt5`
`x = -2/2 +- 2sqrt5/2= -1 +- sqrt5`
graph{x^2 + 2x - 4 [-10, 10, -5, 5]}