SOLUTION: An oil tanker and a cruise ship leave port at the same time and travel straight-line courses at 10 mi/h and 25 mi/h, respectively. Two hours later they are 40 mi apart. What is the

Algebra ->  Trigonometry-basics -> SOLUTION: An oil tanker and a cruise ship leave port at the same time and travel straight-line courses at 10 mi/h and 25 mi/h, respectively. Two hours later they are 40 mi apart. What is the      Log On


   



Question 43167: An oil tanker and a cruise ship leave port at the same time and travel straight-line courses at 10 mi/h and 25 mi/h, respectively. Two hours later they are 40 mi apart. What is the angle between their courses?
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
If you draw the triangle diagram, you get a triangle with sides 20, 50 and 40 miles...now use the law of cosines...
c^2 = a^2 + b^2 - 2ab cos C
40^2 = 20^2 + 50^2 - 2(20)(50) cos C
1600 = 400 + 2500 - 2000 cos C
so that
cos C = .65
and
C = 49.46 degrees