91Ó°ÊÓ

An equation whose graph is a line is called a(n) ?.

Spacecraft in 1997, the Pathfinder spacecraft landed on Mars. It contained a robotic vehicle named Sojourner that could roam up to 500 meters from the lander. The distance d (in meters) that Sojourner could travel in t hours is given by$d=24t$. How long would it take Sojourner to reach its maximum distance from the lander?

1. Copy and complete the table using the given equation

2. Use your completed table to graph $d=24t$.

3. Find the point on the graph whose d-coordinate is 500, and estimate the t-coordinate of this point. How much time would it take Sojourner to reach its maximum distance from the lander?

Copy and complete using always, sometimes, or never: A relation is ? a function.

Tell whether the ordered pair is a solution of the equation.

The height of a person is measured every year from the age of 1 year to the age of 50 years.

1. Do the ordered pairs $\left(\text{age},\text{height}\right)$ represent a function? Explain.
2. Would you expect the ordered pairs $\left(\text{height,age}\right)$ to represent a function? Why or why not?

A skydiver uses an altimeter to track altitude so that he or she knows when to open the parachute. The altimeter determines altitude by measuring changes in atmospheric pressure. The graph below shows how pressure varies with altitude as a skydiver falls from 12,000 feet to ground level. (The elevation of the ground is assumed to be 0 feet with respect to sea level.)

1. As a skydiver fall, does the atmospheric pressure increases or decreases?
2. Describe the domain and range of the relation represented by the graph.
3. Is the relation a function? Explain.
4. Some altimeters can sound an alarm warning a skydiver to open the parachute when the altitude falls to a certain level. If the alarm is set to go off at an altitude of 3000 ft, approximately what atmospheric pressure will trigger the alarm?

To form the inverse of a relation represented by a set of ordered pairs, you switch the coordinates of each ordered pair. For example, the inverse of relation. $\left(1,2\right),\left(3,4\right),\left(5,6\right)\text{is}\left(2,1\right)\text{,}\left(4,3\right)\text{,}\left(6,5\right)$. Give an example of a relation that is a function, but whose inverse is not a function.

Find the value of athat makes the ordered pair a solution of the equation.

The table shows the amount charged for standard ground shipping by an online electronics store.

1. Is shipping cost a function of merchandise cost? Explain.
2. Is merchandise cost a function of shipping cost? Explain.

Represent the relation as a graph and as a mapping diagram. Then tell whether the relation is a function. Explain your reasoning.

$\left(-2,-1\right),\left(0,2\right),\left(2,3\right),\left(-2,-4\right)$