Tasks
Instructions
    Quick theory overview:
  • The last non-zero remainder in the euclidean division algorithm gives the GCD.
  • The GCD h(x) can be expressed as the linear combination of f(x) and g(x) i.e. h(x)=r(x)f(x)+s(x)g(x) where f(x) is the dividend and g(x) is the divisor.

    Procedure:
  • Using landscape mode is recommended on mobile phones and other smaller screens.
  • Polynomials can be entered in the fields provided. Use only lower case x in the field.
  • Expressions like x2 can be entered in the field by typing x^2 on the keyboard.
  • 1, x, +, x^2, x^3 and their combinations need to be entered in the fields in this task. Do not enter any other symbols.
  • Enter the values in all the fields of a row and click on Submit.
  • The correctness of the entered answer is displayed in Observations.
  • If the answer is correct, proceed to the next row. Values in the fields of a row cannot be entered without completing the previous row correctly.
  • Repeat this process until all the rows are filled and the algorithm is complete when a success message displaying the GCD appears in Observations.
  • Next - Displays the next example.
  • Previous - Displays the previous example.


Compute the GCD of x5+x2+x+1 and x3+x2+x+1 over GF(2) using the extended Euclidean Division Algorithm.


Remainder r(x) s(x) Quotient
x5+x2+x+1 1 0

x3+x2+x+1

0

1
0

Observations