Question

How do you graph `y = -x^2 + 3`?

Answer 1

Refer Explanation section.

Explanation:

It has no `x` term in it. You supply -

`y = -x^2 +0x+3`

vertex formula `(-b)/(2a)`
Find the vertex
`x=(-b)/(2a)=0/(2 xx 1)=0`
Its vertex is at `x = 0`
Find a few numbers on either side of zero.
Find their `y` values.
Plot the pairs on a graph sheet.
Join them with a smooth curve.

x: y
-3: -6
-2: -1
-1: 2
0: 3
1: 2
2: -1
3: -6

graph{-x^2 +3 [-10, 10, -5, 5]}