What is the rang y=-x2 - 2x + 3?

Question

asked Oct 10, 2020 61.4k views

1 Answer

Reiko · Answer 1 · 2020-10-14T14:43:29+0000

This is a downward facing parabola, so its range comes in the form

$(-\infty, m)$ where m is the y coordinate of the vertex of the parabola.

We can find the x coordinate of the vertex using

x=-(b)/(2a)=-(-2)/(-2)=-1

And if we plug -1 in the equation we get the y coordinate of the vertex:

y=-(-1)^2-2(-1)+3 = -1+2+3=4

So, the range is the interval

$(-\infty, 4)$