An airplane leaves an airport and flies due west 150 miles and then 170 miles in the direction S 49.17°W. How far is the plane from the airport (round to the nearest mile)?

Question

anonymous · Answer

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jim_thompson5910 · Answer

use the law of cosines to find the value of c


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c^2 = a^2 + b^2 - 2*a*b*cos(C)


c^2 = 150^2 + 170^2 - 2*150*170*cos(49.17)

....

....

c = ???

jim_thompson5910 · Answer

oh wait, C isn't 49.17

C is 49.17+90 = 139.17

so it should be 

c^2 = 150^2 + 170^2 - 2*150*170*cos(139.17)