Spiegare i passaggi.
x^3/(x^2 - 4·x + 3) = (13·x - 12)/((x - 1)·(x - 3)) + (x + 4)
poi poni:
(13·x - 12)/((x - 1)·(x - 3)) = a/(x - 1) + b/(x - 3)
(13·x - 12)/((x - 1)·(x - 3)) = (x·(a + b) - 3·a - b)/((x - 1)·(x - 3))
{a + b = 13
{- 3·a - b = -12
risolvo: [a = - 1/2 ∧ b = 27/2]
(13·x - 12)/((x - 1)·(x - 3)) = 1/(2·(1 - x)) + 27/(2·(x - 3))
x^3/(x^2 - 4·x + 3) = 1/(2·(1 - x)) + 27/(2·(x - 3)) + (x + 4)
Quindi:
∫(x^3/(x^2 - 4·x + 3)dx= 27·LN|x - 3|/2 - LN|x - 1|/2 + x^2/2 + 4·x + C