R Bridge Week 1 Assignment

knitr::opts_chunk$set(echo = TRUE)

#1. Write a loop that calculates 12-factorial
#NOTE: Would replace 1:12 with 1:n and uncomment lines 19 and 25 to base the factorial on input
#n = as.integer(readline(prompt="Input number: "))
f = 1
for(x in 1:12) {
f = f * x
}
print(paste("12- factorial =",f))

## [1] "12- factorial = 479001600"

#print(paste(n,"- factorial =",f))

#2. Show how to create a numeric vector that contains the sequence from 20 to 50 by 5. 

vector = c(seq(from = 20, to = 50, by = 5))

print(vector)

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

#3. Create the function “quadratic” that takes a trio of input numbers a, b, and #c and solve the quadratic
#equation. The function should print as output the two solutions.

a = as.numeric(readline(prompt="Input number a: "))

## Input number a:

b = as.numeric(readline(prompt="Input number b: "))

## Input number b:

c = as.numeric(readline(prompt="Input number c: "))

## Input number c:

quadratic<-function(a,b,c){
  if(delta(a,b,c)>0){
    x1 = (-b+sqrt(delta(a,b,c)))/(2*a)
    x2 = (-b+sqrt(delta(a,b,c)))/(2*a)
    quadratic = c(x1,x2)
    
  }
  else if(delta(a,b,c)==0){
    x=-b/(2*a)
  }
  else {"No Roots"}
}

delta<-function(a,b,c){
  b^2-4*a*c
  
}


print(quadratic(a,b,c))

## Error in if (delta(a, b, c) > 0) {: missing value where TRUE/FALSE needed