"A Boeing 747 crosses the Atlantic Ocean (3000 miles) with an airspeed of 500 mph. The cost C (in dollars) per passenger is given by
C(x)=50+x/10+34,000/x
where x is the ground speed (airspeed ± wind).
a) Graph the function C=C(x).
Graph C for 0≤x≤1000 and 0≤y≤1000 using a graphing utility.
b) Create a TABLE with TblStart=0 and Tbl=50. To the nearest 50 mph, what ground speed minimizes the cost per passenger?" a) Press the "y=" key (right under the screen) and on the first line, enter the following:
50+(x/10)+(34,000/x)
The x key in the upper left of the keypad -- just right of the alpha key
press the window key (right under the screen) and change the x min = 0 and the x max = 1000 (use the arrow keys on the right to move from one line to the next)
change the y min = 0 and the y max = 1000
Now press the graph button (just below the screen) and you'll see the graph
Press the table set key (press 2nd and then window). change the tblset = 0 and the tbl = 50
Now....either press 2nd and then the graph key to see a table of values, or if you press 2nd and trace (just to the left of the graph key), you can choose #3 (minimum) to find the minimum y (cost) value. To do this, use the left arrow to move to the left of the graph and hit enter (this sets the left boundary for the calculator to search). Then use the right arrow to move all the way to the right to set the right boundary. Hit enter a second time and the coordinates of the minimum value will display at the bottom of the screen. Round your x value to the nearest 50 and you have your answer.