i lack the knowledge in some area of polar coordenates(adsbygoogle = window.adsbygoogle || []).push({});

my problem is:

i was given a two points and an angle

one point is the center point the other is the the point we spin around the

center point by the given angle(rotation clock wise).

i have build a model to solve this problem by

slope=(y-center.y)/(x-center.x);

fi=arctan(slope);

beta=fi-angle;

xi=rad*cos(beta);

yi=rad*sin(beta);

x=center.x+xi;

y=center.y+yi;

but in a case of 2,1 as a center point

and 0,0 as the point we want to spin

when i spined it 90 deress(clock wise)

by this model i gave me a wronge answer (the right one is 1,3)

so by tryle and error method i found that we need to add 180 degrees

i dont know why

i dont know how to solve this problem

??

i want a solution for all the cases

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# Mathematical problem

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