Question

How do you graph the function, label the vertex, axis of symmetry, and x-intercepts. `y= -2x^2 - 5x +7`?

Answer 1

`y = -2x^2 - 5x + 7`
Axis of symmetry: `x = -b/2a = -5/4`
Coordinate of vertex: `x = -5/4 and y = f(-5/4) = 25/8 + 56/8 = 81/8`
To get x-intercepts: solve `y = - 2x^2 - 5x + 7 = 0.`

Since a + b + c = 0, then one real root is (1), and the other is (c/a = -7/2). Intercepts: -7/2 and 1.

graph{-2x^2 - 5x + 7 [-10, 10, -5, 5]}