## Intro to R
## Exercise 1

## Question 2
sqrt(22^2+8)/((factorial(3)+1)*8*pi)

## Question 3
aa<-c(3,5,3,4,6,5,1,8,3,2,4,5,3,6,4,2,4)

#(a)
length(aa)
mean(aa)
var(aa)
range(aa)

#(b)
hist(aa)

#(c)
bb<-rev(sort(aa))
bb

#(d)
cc<-aa[aa>3]
cc

#(e)
dd<-aa
dd[dd>1&dd<3]<-NA

#or
dd<-aa
dd[dd==2]<-NA
dd

#or
dd<-aa
d<-which(aa==2)
dd[d]<-NA
dd

#or
dd<-aa
dd[which(aa==2)]<-NA
dd

#(f)
mean(dd,na.rm=TRUE)


## Question 5
loto<-1:49
sample(x=loto,size=6,replace=FALSE)
sample(loto,size=6,replace=FALSE)

## Question 6
install.packages("car")
library(car)
?some