自定义一元n次函数，根据定义的函数及其值域绘制曲线，并且对已知曲线进行多种运算，例如：求导，微分，曲率，去杂点，平滑等等。-N times one dollar custom function, by definition, the function and range of drawing curves, and a variety of computing known curve, for example: derivation, derivative, curvature, to the