Question 1151319
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You have a unit circle and a given point on it.


When you add/subtract {{{pi}}}, it is the same as to rotate the unit circle by the angle  {{{pi}}}  anticlockwise or clockwise, respectively.



In any case, your point will be transformed to the opposite point in the circle,

changing the original x- and y- coordinates to opposite numbers.



In your case, the transformed point will be  (5/13,12/13).      <U>ANSWER</U>
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