//
// preliminary version of function to calculate and print
// roots of quadratic equation
// a*x*x + b*x + c = 0
// prints message if no real (non-imaginary) roots
//
def roots(a : Double, b : Double, c : Double) {
  println("a = " + a + ", b = " + b + ", c = " + c)
  if ((b*b - 4*a*c) >= 0) {
    val root1 = (-b + math.sqrt(b*b - 4*a*c))/(2*a)
    val root2 = (-b - math.sqrt(b*b - 4*a*c))/(2*a)
    println("roots " + root1 + ", " + root2)
  }
  else {
    println("No real roots")
  }
}