Big Ideas Math Integrated I, 2016
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Big Ideas Math Integrated I, 2016 View details
1. Writing Equations in Slope-Intercept Form
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Exercise 24 Page 169

Start by using the Slope Formula to find the slope.

f(x)=3

Practice makes perfect
An equation in slope-intercept form follows a specific format. In this case, we are asked to write our equation in function notation. f(x)= mx+ b For an equation in this form, m is the slope and b is the y-intercept. We have also been given two points in function notation. To write these points as coordinate pairs, remember that the input x is the x-coordinate and the output f(x) is the y-coordinate. f( x)= y ⇔ ( x, y) f( 0)= 3 ⇔ ( 0, 3) f( -6)= 3 ⇔ ( -6, 3) Let's use the given points to calculate m. We will start by substituting the points into the Slope Formula.
m=y_2-y_1/x_2-x_1
m=3-3/- 6-
â–Ľ
Evaluate right-hand side
m=0/-6
m=0
A slope of 0 means that for every 1 horizontal step in the positive direction, we take 0 vertical steps. Therefore, we have a horizontal line. Now that we know the slope, we can write a partial version of the equation. f(x)= 0x+ b To complete the equation, we also need to substitute the y-intercept, b. We can see that one of our given points, (0, 3), lies on the y-axis. Since the line crosses the y-axis at this point, we know the y-intercept and can complete the equation. f(x)= 0x+ 3 ⇔ f(x)=3