Spiegare i passaggi.
1/(x^4 - x^3) = 1/(x^3·(x - 1))
poniamo:
1/(x^4 - x^3) = a/(x - 1) + b/x^3 + c/x^2 + d/x
1/(x^4 - x^3) = (x^3·(a + d) + x^2·(c - d) + x·(b - c) - b)/(x^3·(x - 1))
Quindi sistema:
{a + d = 0
{c - d = 0
{b - c = 0
{-b = 1
Risolvo: [a = 1 ∧ b = -1 ∧ c = -1 ∧ d = -1]
1/(x^4 - x^3) = 1/(x - 1) - 1/x^3 - 1/x^2 - 1/x
quindi:
∫(1/(x^4 - x^3))dx= LN|x - 1| - LN|x| + 1/x + 1/(2·x^2) + C