Solve each of the following equations by using the method of completing the square:

x2 - 4x + 1 = 0

Given: x2 - 4x + 1 = 0

x2 - 4x = - 1


x2 - 2.x.2 + 22 = - 1 + 22 (adding 22 on both sides)


(x - 2)2 = - 1 + 4 = 3 using a2 - 2ab + b2 = (a - b)2


(taking square root on both sides)




Hence the roots of equation are


2