x = [0.000:0.001:0.500];
f = 1./(1-x);
t1 = 1+x;
t2 = 1+x+x.^2;
t3 = 1+x+x.^2+x.^3;
t4 = 1+x+x.^2+x.^3+x.^4;
plot(x,f,x,t1,x,t2,x,t3,x,t4);