This image represents points (x,y) that satisfy the equation:

π
/4 = tan^{-1}(y_{1}/x_{1})
+ tan^{-1}(y_{2}/x_{2})
− tan^{-1}(y_{3}/x_{3}).

The image is made up of hundreds of
Lagrange polynomial curves,
each defined by the points (x_{1},y_{1}), (x_{2},y_{2}),
and (x_{3},y_{3}).

© 2013 Kerry Mitchell