R Week 1 HW

Question1

factorial <- 1
for(q in 1:12)
{
  factorial = factorial * q
}
print(paste("12! = ", factorial))

## [1] "12! =  479001600"

Question 2

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

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

Question 3

quadratic <- function(a,b,c)
{
  if(a == 0)
     {
       return("This is not a quadratic equation")
     }
  discriminant <- (b ^ 2) - (4 * a * c)
  if(discriminant == 0)
  {
    root1 = (- b / (2 * a))
    return(print(paste("There is only one solution = ", root1)))
    
  }
  else if(discriminant > 0)
  {
    root1 = (- b + sqrt(discriminant)) / (2 * a)
    root2 = (- b - sqrt(discriminant)) / (2 * a)
    return(print(paste("There are two solutions = ", root1, "and ", root2)))
  }
  else
  {
    root1 = (complex(real = - b / (2 * a), imaginary = (sqrt(-discriminant) / (2 * a)))) 
    root2 = (complex(real = - b / (2 * a), imaginary = (- sqrt(-discriminant) / (2 * a))))
    return(print(paste("There are two complex solutions = ", root1, "and ", root2)))
  }
}
quadratic(2,3,1)

## [1] "There are two solutions =  -0.5 and  -1"

Another Example for Question 3 showing complex solutions

quadratic(4,6,3)

## [1] "There are two complex solutions =  -0.75+0.433012701892219i and  -0.75-0.433012701892219i"

Another Example for Question 3 showing a = 0

quadratic(0,2,-3)

## [1] "This is not a quadratic equation"

Another Example for Question 3 showing only one solution

quadratic(2,4,2)

## [1] "There is only one solution =  -1"