R=inline('1/(1+x^2)','x');
fplot(R,[-5,5],'g');
hold on
fplot(@N,[-5 5],'k');
hold on
fplot(@L,[-5 5],'b');
hold on
fplot(@Liner,[-5 5],'r');
hold on
fplot(@Hermite,[-5 5],'y');
hold on
fplot(@Sanciyangtiao,[-5 5],'c');