A boat travels in a straight line at constant speed. Initially the boat has position (-11 - 2j km relative to a fixed origin O
After 90 minutes the boat has position (i + 6j km relative to O
(a) Show that the speed of the boat is p 13 km h', where p is a constant to be found. The boat continues in the same direction until it reaches point X
Given that X is due north east of O
(b) find the position vector of X, making your method clear. (3)
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