JAMB - Mathematics (1983 - No. 30)
A ship H leaves a port P and sails 30 km due south. Then it sails 60km due west. What is the bearing of H from P?
20o 34'
243o 26'
116o 34'
63o 26'
240o 56'
Explication
Let the bearing of H from P be represented by x°.
\(\tan \theta = \frac{30}{60} = 0.5\)
\(\theta = \tan^{-1} (0.5) = 26.565°\)
\(x = 180° + (90 - 26.565)\)
\(x = 180 + 63.435 = 243.435°\)
= \(243° 26'\)