Simultaneous solving of equations – who knew it would come to this?

Oh yeah.  I had a shoulder line with a slope.  Needed to make a  dart perpendicular to shoulder line at the midpoint. Aha!  Get slope of shoulder line, negate & invert to get perpendicular slope.  Use midpoint as center point of circle. Solve line and circle equations simultaneously.   My issues were that python doesn’t like ^ for exponents, likes ** instead.  Use as many parentheses as you can possibly stand, didn’t get the right results with  r / (1+m**2)**(1/2) .   This was changed to (r/((1+m**2)**(.5))) and it worked perfectly.  And did you notice my Quadratic Bezier Curve?