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?

20^o 34'

243^o 26'

116^o 34'

63^o 26'

240^o 56'

Let the bearing of H from P be represented by x°.

\(\tan \theta = \frac{30}{60} = 0.5\)

\(\theta = \tan^{-1} (0.5) = 26.565°\)

\(x = 180° + (90 - 26.565)\)

\(x = 180 + 63.435 = 243.435°\)

= \(243° 26'\)