t=0:0.001:23*pi/36;
x=-(40+25*(1-cos(36*t/23)).*cos(t)+15*sin(t);
y=(40+25*(1-cos(36*t/23)).*sin(t)+15*cos(t);
dx1=diff(x);
dy1=diff(y);
dx11=diff(x,2);
dy11=diff(y,2);
p=abs(((dx1.^2+dy1.^2).^(3/2))/(dx1.*dy11-dy1.*dx11));
hold on
plot(t,p);
怎么解决这个问题