1.1 Graphs and Graphing Utilities
∙ Read this review section in your textbook (Section 1.1)
A. Graphs of Equations (Idea)
1. Make a table of (𝑥, 𝑦) points by plugging in numbers for 𝑥 and figuring out 𝑦.
2. Plot the points on a grid.
3. Connect the dots.
B. Intercepts
𝑥-intercept:
𝑥-value where graph crosses the 𝑥-axis
𝑦-intercept:
𝑦-value where graph crosses the 𝑦-axis
To find:
To find 𝑥-intercept(s): set 𝑦 = 0
To find 𝑦-intercept(s): set 𝑥 = 0
Example:
2𝑥 + 3𝑦 = 6
Then 𝑥 = 0 =⇒ 3𝑦 = 6 =⇒ 𝑦 = 2
𝑦-intercept
Then 𝑦 = 0 =⇒ 2𝑥 = 6 =⇒ 𝑥 = 3
𝑥-intercept
1
C. Calculator Graphing Window Notation
[ xmin, xmax, tick distance] by [ ymin, ymax, tick distance]
distance
leftmost on
between
𝑥-axis
rightmost on tick marks
𝑥-axis
Example:
leftmost on
𝑦-axis
distance
between
tick marks
rightmost on
𝑦-axis
[-10,5,5] by [-3,4,1]
means:
𝑦
4
3
2
1
-10
-1 0
-2
-3
-5
2
𝑥
5