rajBridgeAssignment1

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Assignment 1: Rajesh Kumar

Q1: Write a program to calculate 12 factorial

compute_factorial <- function(x){
  # take input from the user

  if (x < -1){
    return (-1)
  } else if (x == 0) {
    return (0)
  } else {
    value <-  1
    # for loop to calculate the value
    for(i in 1:x) {
      value = value * i
    }
    return (value)
  }
}

# Call the function and print the value  
factorial <- compute_factorial(12)
print (factorial)

## [1] 479001600

Q2: Show how to create a numeric vector that contains the sequence from 20 to 50 by 5.

# Create a seq by specifiying the start, end and interval values
y <- c(seq(20,50,5))

# Print the vector
print (y)

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

Create the function “factorial” 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.

factorial <- function(a,b,c){
  ##
  # Quadratic equation ax2 + bx + c = 0
  # can be solved with formula below
  # (-b(+_)sqrt(b^2 - 4 * a * c))/(2 * a)
  ##
  
  if(a!=0){
    ##
    # Breaking the formula into 2 parts for simplicity
    # val is common
    # x1 and x2 are computed by their respective +- signs
    ##
    val  <-  sqrt(b^2 - 4 * a * c)
    x1 <- (-b - val) / (2 * a)
    x2 <- (-b + val) / (2 * a)
    return(sprintf ("The quadratics equation (%s,%s,%s) has answers %s and %s",a,b,c,x1, x2))
  }else{
    return (sprintf ("(%s,%s,%s) is not an quadratic equation!",a,b,c))
  }
  
}

factorial(1,-1,-2)

## [1] "The quadratics equation (1,-1,-2) has answers -1 and 2"

factorial(1,-3,-4)

## [1] "The quadratics equation (1,-3,-4) has answers -1 and 4"

factorial(1,0,-4)

## [1] "The quadratics equation (1,0,-4) has answers -2 and 2"

factorial(6,11,-35)

## [1] "The quadratics equation (6,11,-35) has answers -3.5 and 1.66666666666667"

factorial(0,11,-35)

## [1] "(0,11,-35) is not an quadratic equation!"