Big Ideas Math Algebra 2, 2014
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Big Ideas Math Algebra 2, 2014 View details
1. Parent Functions and Transformations
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Exercise 60 Page 10

You'll need to substitute 0 for both variables and solve.

x-intercept: -2
y-intercept: 2

Practice makes perfect

To determine the x- and y-intercepts of a line we need to substitute 0 for one variable, solve, then repeat for the other variable.

Finding the x-intercept

Think of the point where the graph of an equation crosses the x-axis. The y-value of that ( x, y) coordinate pair is 0, and the x-value is the x-intercept. To find the x-intercept of the equation, we should substitute 0 for y and solve for x.
y=x+2
0=x+2
-2=x
x=-2
An x-intercept of -2 means that the graph passes through the x-axis at the point ( -2,0).

Finding the y-intercept

We could use the same concept to find the y-intercept, but take a close look at the given equation. y=x+ 2 The given equation is in slope-intercept form, y=mx+ b. For an equation in this form, we know that the constant b represents the y-intercept. Therefore, the y-intercept is 2, and the graph passes through the y-axis at the point (0, 2).