Example 4.1 The quadratic equation

This is basic example showing how to use  the if statement and one of the key examples for learning how to develop simple algorithms. Note, for the simplicity of the algorithm we do not consider  here all cases that we should consider while solving quadratic equations.

a := 1:

b := -21:

c := 3:

if a<>0 then

   delta := b^2 - 4*a*c;

   if delta >= 0 then

      x1 := (-b + sqrt(delta))/(2*a);

      x2 := (-b - sqrt(delta))/(2*a);

      print(Typeset, x1, x2)

   else

      print("No real solutions")

   end_if

else

   if b<>0 then

      x1 := -c/b

   else

      print("No solutions")

   end_if

end_if

© Miroslaw Majewski, Abu Dhabi,  Update  26-10-2004