Solve Apps: Polar Coordinates
-The Wind Is Blowing at 10 $10 - k n o t$

Solve Apps: Polar Coordinates
-The wind is blowing at 10 knots. Sailboat racers look for a sailing angle to the $10 - k n o t$ wind that produces maximum sailing speed. In this application, $( r , \theta )$ describes the sailing speed $r$ , in knots, at angle $\theta$ to the 10 -knot wind. Four points in this 10 -knot-wind situation are $\left( 6.6,55 ^ { \circ } \right) , \left( 7.4,80 ^ { \circ } \right) , \left( 7.5,110 ^ { \circ } \right)$ and $\left( 7.3,130 ^ { \circ } \right)$ . Based on theses points, which sailing angle to the $10 - \mathrm { knot }$ wind would you recommend to a serious sailboat racer? What sailing speed is achieved at this angle?

A) $110 ^ { \circ } ; 7.5$ knots
B) $130 ^ { \circ } , 7.3$ knots
C) $55 ^ { \circ } ; 6.6$ knots
D) $80 ^ { \circ } ; 7.4$ knots