First, we'll impose the constraint of existence of square
            root;
x>=0
1 +
            sqrtx>=0
We'll subtract 1 both
            sides:
x - 1 = sqrt[1 +
            sqrt(x)]
We'll raise to square both sides, to eliminate the
            square root from the right side:
(x-1)^2 = 1 + sqrt
            x
We'll expand the square:
x^2
            - 2x + 1 = 1 + sqrtx
We'll eliminate like
            terms:
x^2 - 2x = sqrt x
We'll
            raise to square:
(x^2 - 2x)^2 =
            x
[x(x - 2)]^2 - x = 0
We'll
            factorize by x:
x[x(x-2)^2 - 1] =
            0
x1 = 0
x(x-2)^2 - 1 =
            0
We'll expand the square:
x^3
            - 4x^2 + 4x - 1 = 0
We'll factorize the middle terms by
            -4x:
(x^3 - 1) - 4x(x - 1) =
            0
We'll re-write the difference of
            cubes;
x^3 - 1 = (x - 1)(x^2 + x +
            1)
(x - 1)(x^2 + x + 1) - 4x(x - 1) =
            0
We'll factorize by
            (x-1):
(x-1)(x^2 + x + 1 - 4x) =
            0
x - 1 = 0
x2 =
            1
x^2 - 3x + 1 = 0
We'll apply
            the quadratic formula:
x3 = [3+sqrt(9 -
            4)]/2
x3 = (3 + sqrt5)/2
x4 =
            (3 - sqrt5)/2
The solutions of the equation
            are: {0 ; (3 - sqrt5)/2 ; 1 ; (3 + sqrt5)/2}.
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