The general form of equations for conic sections is ,
Where and are constants .
Width of the opening light is much greater than the width of second light.
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, ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=fb05b636a7fe35515439da0d9f54d62d.png\")
and ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=dc9f8ffcab337592beb01514378d64b4.png\")
are constants .![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
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much greater than the width of second light.