Question

in june 1990, the temperature in phoenix, Arizona rose to 122F. Could the pilot have taken off on this day? Why or why not?

Answer 1

A pilot is flying a CRJ-900 from Phoenix, Arizona, to Louisville, Kentucky. The aircraft cannot take off or land if the temperature on the field is not within its operating
limitations. The aircraft cannot operate if the temperature is at or below -40°F, or at or above 118° F.

Part A: Write an inequality to represent the temperatures the pilot can take off and land in. (2 points)
Part B: Describe the graph of the inequality completely from Part A. Use terms such as open/closed circles and shading directions. Explain what the solutions to the
inequality represent. (4 points)

Part C: in June 1990, the temperature in Phoenix, Arizona rose to 122° F. Could the pilot have taken off on this day? Why or why not? (4 points)

Answer 2

part A: the temperature must *not* be "at or below -40"

so if the temperature is x, x must be greater than -40, so we have -40 < x so far
it must also "not" be at or above 118, so x < 118

combined: -40°F < x < 118°F

Answer 3

part B: because we have < symbols, we use open circles on -40 and 118. we want the values between -40 and 118, draw the line connecting -40 and 118 on the graph, showing that all values between -40 and 118 are included

part C: there's a couple of ways you could do this. you could check the graph to see if 122 is included in the graph, or you could plug x = 112 into the inequality to see if it's still true.