摘要：
pair f(real t){ real x=(1-t^2)/(1+t^2); real y=t*(1-t^2)/(1+t^2); return (x,y); } draw(graph(f,-2,2),red); /* real x(real t) {return (1-t^2)/(1+t^2);} real y(real t) {return t*(1-t^2)/(1+t^2);} draw(graph(x,y,-2,2),red); */不是很懂，慢慢来 阅读全文
摘要：
point A=(0,0);real a=5, b=4;ellipse el=ellipse(A,a,b);draw(el,linewidth(1mm));dot("$A$",el.C,N,red);——————如果只画第一象限的部分，奇怪的是下面这段代码不行real f(real x) {return sqrt(5-(2x)^2);}pair F(real x) {return (x,f(x));}draw(graph(f,0,sqrt(5/2),operator ..),red+linewidth(0.8)); 阅读全文