x<-(0:2500)/1000
clip<-function(x,y) ifelse(x>2,1,ifelse(x<0,0,y))
plot(x, clip(x,1-0.5*(2-x)), pch=".", xlab="x", ylab="P(X<=x)")
points(x, clip(x,1-(0.5*(2-x))^2), pch=".")
points(x, clip(x,1-(0.5*(2-x))^3), pch=".")