Load the dplyr packages.

library(dplyr)

Calculate 12-factorial

factorial = 1
for(i in 1:12) {
factorial = factorial * i}
print(paste("The factorial of", "12" ,"is",factorial))

## [1] "The factorial of 12 is 479001600"

Create a numeric vector that contains the sequence from 20 to 50 by 5

NV <- seq(20, 50, 5)
NV

## [1] 20 25 30 35 40 45 50

Solve Quadratic Equation ax2+bx+c=0

#Calculation
a<-2
b<-4
c<--4
result1<-(-b-sqrt((b^2)-4*a*c))/(2*a)
result2<-(-b+sqrt((b^2)-4*a*c))/(2*a)
cat('result 1: ', result1)

## result 1:  -2.732051

cat('result 2: ', result2)

## result 2:  0.7320508