Two canoeists are paddling a canoe. Vector analysis

Question

Two canoeists are paddling on opposite sides of a canoe. One extends her arms out so that the force of 15lbs she exerts is directed backwards at an angle of 22 degrees with the canoe. The other extends her paddle so that the force she exerts is at an angle of 13 degrees with the canoe. If they want the canoe travel straight ahead, with what force should the second paddler paddle?

Answer 1

Assume the canoe points along +x. Then the let the first canoist be exerting a force at an angle with respect to -x of and the second at an angle To move straight ahead we must have