How do you graph the equation by plotting points $y=x^2-9$ ?

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Answer 1 · 2018-07-16T15:07:26

Please see below.

Observe that when $x=0$ , we have $y=-9$ .

This means two things -

(1) Point $(0,-9)$ lies on the curve and

(2) this is the minimum value of $y$ and as $x$ moves on either side of $x=0$ , $y$ rises from its value of $-9$ .

When $x=+-2$ , $y$ is $-5$ , when $x$ is $+-4$ , $y$ is $7$

when $x=+-6$ , $y$ is $27$

This means curve passes through $(2,-5),(-2,-5),(-4,7),(4,7),(-6,27)$ and $(6,27)$

Joining them we get the curve as follows:

graph{x^2-9 [-41.83, 38.17, -11.04, 28.96]}

How do you graph the equation by plotting points y=x^2-9y=x^2-9?