Shana Green

R Bridge

HW 1

Due 07/19/20

1. Write a loop that calculates 12-factorial**

factorial <- 1 
for (i in 12:1) { 
     factorial = factorial * i 
      }
factorial

## [1] 479001600

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

numvec <-c(seq(20,50, by = 5))
numvec

## [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.**

quadratic<- function(a, b, c){
    

    discriminant = (b^2) - (4*a*c)

            if (discriminant< 0) 
                {
                
                return(print("No real roots!"))
            }
    
                else if (discriminant > 0) {
                    
                    posroot <- (-b + sqrt(discriminant)) / (2*a)
                    negroot <- (-b - sqrt(discriminant)) / (2*a)
                    
                    return(posroot)
                    return(negroot)
                }
                     else {
                         x_intercept <- (-b)/ (2*a)
                     return(print("This quadratic equation has only one root. The root is ", x_intercept))
                           }

    }
quadratic(1,6,5)

## [1] -1

I was unable to tweak program to print double negative roots!"]