9514 1404 393
Answer:
140.2°
Step-by-step explanation:
The direction of vector (x, y) is the angle arctan(y/x). The signs of the components tell you this is a 2nd quadrant angle. The arctan function only gives values in the range -π/2 to +π/2, so 180° must be added for 2nd and 3rd quadrant angles.*
arctan(5/-6) = 180° -39.8° = 140.2° . . . . CCW from the +x axis
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* Spreadsheets and some calculators have an ATAN2(x, y) function that uses the signs of the coordinates to give the result in the correct quadrant.
