Idiot\'s Guides Basic Math and Pre-Algebra

138 Part 2: Into the Unknown

WORLDLY WISDOM

If the coefficient of x is a fraction, choose x-values that are divisible by the

denominator of the fraction. This will minimize the number of fractional coordinates,

which are hard to estimate.

Once you have a line of points, connect them and extend the lines in both directions. Add an

arrow to each end to show that the line continues.

When you build a table of values, make a habit of choosing both positive and negative values for x.

Of course, you can choose x = 0, too. Usually, you’ll want to keep the x-values near zero so that

the numbers you’re working with don’t get too large. If they do, you’ll need to extend your axes,

or re-label your scales by twos or fives, or whatever multiple is convenient.

-6 -2 062

-2

2

4

6

-4

-6

-8-9 -7 -5 -4 -1-3 134 5 78 9

-8

-9

-1

-3

-5

-7

8

9

1

3

5

7

-10 10

-10

10

y

x

(-2,6)

(-1,4.5)

(0,3)

(1,1.5)

(2,0)