a Notice that remaining distance will decrease after each minute.
B
b In order to find the intercepts, substitute 0 for each of the variables and then solve the equation for the other variable.
A
aFunction: f(x)=2-1/15x
Graph:
B
bx-intercept: 30
y-intercept: 2 Interpretation: See solution.
Practice makes perfect
a We are told that Kathryn needs 30 minutes to complete 2-mile walk. With this information we can calculate her pace.
distance/time=2/30=1/15
Let's write a function f(x) where x represents the number of minutes that have passed and f(x) is the remaining distance. Therefore, in the beginning the distance is 2 miles and decreases by the pace multiplied by the number of minutes that have passed.
f(x)= 2-1/15x
Next, we will graph the function by creating a table of values.
x
2-1/15x
f(x)
6
2-1/15( 6)
1.6
12
2-1/15( 12)
1.2
18
2-1/15( 18)
0.8
24
2-1/15( 24)
0.4
Now, let's plot the points and draw the function.
b In this part, we will find and interpret the interception points. Let's find the x-intercept first. To do so, we will substitute 0 for f(x).
