We'll re-write the numerator
as:
x^3 - 3x - 2 = x^3 - x - 2x -
2
We'll factorize the first 2 terms and the last 2
terms:
x^3 - x - 2x - 2 = x(x^2 - 1) - 2(x +
1)
The difference of squares x^2 - 1 = (x - 1)(x +
1)
x^3 - x - 2x - 2 = x(x - 1)(x + 1) - 2(x +
1)
We'll factorize again by (x +
1):
x^3 - x - 2x - 2 = (x + 1)[x(x+1) -
2]
x^3 - x - 2x - 2 = (x + 1)(x^2 + x -
2)
The roots of the quadratic x^2 + x - 2 are - 1 and
2.
x^3 - x - 2x - 2 = (x +
1)(x+1)(x-2)
We'll re-write the denominator
as:
(x^3+1)+(3x^2+3x)
We'll
re-write the difference of cubes and we'll factorize the last 2
terms:
(x+1)(x^2 - x + 1) + 3x(x + 1) = (x+1)(x^2 - x + 1 +
3x)
(x+1)(x^2 - x + 1) + 3x(x + 1) = (x+1)(x^2 + 2x +
1)
(x+1)(x^2 + 2x + 1) = (x+1)(x+1)^2 =
(x+1)^3
We'll re-write E(x) = (x +
1)^2*(x-2)/(x+1)^3
We'll simplify and we'll
get:
E(x) = (x-2)/(x+1)
We'll
solve the equation:
(x-2)/(x+1) = sqrt3 -
sqrt2
x - 2 = (sqrt3 -
sqrt2)(x+1)
x - x(sqrt3 - sqrt2) = sqrt3 - sqrt2 +
2
x(1 - sqrt3 + sqrt2) = sqrt3 - sqrt2 +
2
x = (sqrt3 - sqrt2 + 2)/(1 - sqrt3 +
sqrt2)
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