# Specify Equations in Graphing Question Answer Keys

When you use line, circle, parabola, or region in your graphing question answer key, you have the option of specifying an equation for the key. You can use the following notation in your equations.

Note:
• Do not use commas or spaces to separate digits in numbers. For example, 1000000 is correct, but 1,000,000 and 1 000 000 are not.
• Do not use mixed numbers. Instead, use improper fractions. For example, 7/4 is correct, but 1 3/4 is not correct.

Expression

Notation

Examples

Math variables

The only allowed variables in graphing question answer keys are x and y.

line: y=x+1

+
line: y=x+1

Subtraction

-
line: y=x-1

Multiplication

*

You must use explicit multiplication.

line: y=x*2

Division or fractions

/
line: y=x/4

Exponentiation

^

Ensure that your equation specifies a linear, circular, or parabolic function.

parabola: y=x^2
circle:(x-1)^2+(y+3)^2=25

Equality

=
line: y=x+1

Inequality

>
<
>=
<=
region: y>x+1
region: y<x+1
region: y>=x^2+3*x+1
region: (x-1)^2+(y+3)^2<=25

Order of Operations

()
circle:(x-1)^2+(y+3)^2=25

Pi (π)

pi

Substituting 3.14 only approximates this value.

parabola: y=pi*x^2