f1 <- function(x) asin(x) f2 <- function(x) acos(x) f3 <- function(x) atan(x) plot(f1,-1,1,ylim=c(-2,pi),col="blue",lwd=2,asp=1,n=1e4) plot(f2,-1,1,asp=1,add=TRUE,lwd=2,n=1e4) plot(f3,-6,6,asp=1,add=TRUE,lwd=2,col="red",n=1e4) plot(f2,-1,1,asp=1,add=TRUE) plot(f1,-1,1,col="blue",add=TRUE,asp=1) abline(h=0,v=0) abline(h=seq(-5,5,1),v=seq(-5,5,1),lty=3) abline(h=pi,lty=2) abline(h=-pi/2,lty=2) abline(h=pi/2,lty=2)