Which of the following is the first step in calculating range?

Arrange the numbers in order of value.
Subtract the smallest number from the largest.
Add the smallest number to the largest.
Plot the data on a number line.

A) y intercept is (0,3)

C) Axis of symmetry is x = -1

D) Vertex is (-1, 4)

So basically everything but choice B is true.

Explanation:

Choice A is true because plugging in x = 0 leads to y = 3. Effectively, anything with an x goes away when x = 0 leaving that 3 behind. So finding the y intercept in this form is fairly fast.

To check choices B through D, let's convert the equation into vertex form.

y = -1x^2 - 2x + 3 is in the form y = ax^2 + bx + c where

a = -1

b = -2

c = 3

The vertex is located at (h,k) such that h = -b/(2a)

Plug the values of 'a' and 'b' into the equation below

h = -b/(2a)

h = -(-2)/(2*(-1))

h = 2/(-2)

h = -1

The x coordinate of the vertex is x = -1

Then use this to find the y coordinate of the vertex

y = -1x^2 - 2x + 3

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

y = 4

The y coordinate of the vertex is 4, meaning k = 4

The vertex overall is (h,k) = (-1, 4)

This shows choice D is true, meaning choice B has to be false.

Choice C is true because the axis of symmetry is the x coordinate of the vertex. This is the vertical line that cuts the parabola into two mirrored halves. This vertical line always goes through the vertex.