e
e <- exp(1)
e
pi
print(pi)
print(pi, dig=10)
?print
outer(1:10, 1:10) 
outer(1:10, 1:10, '+') 
outer(1:10, 1:10, '-') 
outer(1:10, 1:10, '/') 
outer(c(F,T), c(F,T))  
outer(c(F,T), c(F,T), '&')  
outer(c(F,T), c(F,T), '|')  
outer(c(F,T), c(F,T), 'xor')  
v.cil2  <- function(r, h) { area <- pi*r^2; volume<-area*h; return(volume)}
ls()
ls.str()
str(v.cil2)
v.cil2(2, 3)
v.cil2  
ls()
ls
sqrt <- functon(x)  "boh"
sqrt <- function(x)  "boh"
sqrt(4)
base::sqrt(4)
rm(sqrt)
sqrt(4)
r4 <- function(x) x^(1/4)
r4(16)
x = 1:10
x = sqrt(1:10)
x
x[ x > pi]
x[ x > pi/2]
q()