Let’s use the law of cosines to solve this problem. The law of cosines states that for any triangle with sides a, b, and c, and angle C opposite to side c, the following equation holds: c^2 = a^2 + b^2 - 2ab cos. In our case, we know that the patrol boat travels at a speed of 15 knots and the fishing boat travels at a speed of 2 knots. After 1 hour, the fishing boat sends a distress signal, which is picked up by the patrol boat. If the fishing boat does not drift, we can assume that it has traveled 2 nautical miles in one hour . Let’s call the distance between the patrol boat and the fishing boat “d”. We can use the law of cosines to solve for “d” as follows:
d^2 = 15^2 + 2^2 - 2(15)(2)cos(105°) d^2 = 225 + 4 - 60cos(105°) d^2 = 229.8 d ≈ 15.16 nautical miles
Therefore, it will take the patrol boat approximately 1.011 hours to reach the fishing boat at a speed of 15 knots .