posted by Karen .
A airplane is 145 miles North and 85 miles west of an airport. What is the compass direction from the airport to the airplane?
pre calculus -
making a sketch , I got
tanØ = 145/85 = 1.7058...
Ø = 59.62°
Using the standard compass notation (north is zero, go clockwise)
direction is 180 - 59.62° = 120.38°
or sometimes you see it as N 59.62° W
plane is at (-85,145) on a grid , which is in quadrant II
tan Ø = 145/-85
Ø = -59.62° which would be the angle in quadrant IV
or 180 - 59.62 = 120.38 --> our angle