Katyushka
Сообщение
#10694 31.1.2008, 17:29
Помогите, пожалуйста, вычислить интеграл
Black Ghost
Сообщение
#10695 31.1.2008, 19:58
int (-2 1/2) x * [x] dx =
= int (-2 -1) x * [x] dx + int (-1 0) x * [x] dx + int (0 1/2) x * [x] dx =
= int (-2 -1) x * (-2) dx + int (-1 0) x * (-1) dx + int (0 1/2) x * 0 dx =
= int (-2 -1) -2 * x dx + int (-1 0) -x dx =
= (-2 * 1/2 * x^2)_{-2}^{-1} - (1/2 * x^2)_{-1}^{0} =
= (x^2)_{-2}^{-1} - (1/2 * x^2)_{-1}^{0} =
= ((-1)^2 - (-2)^2) - (1/2 * 0^2 - 1/2 * (-1)^2) =
= (1 - 4) + 1/2 = -3 + 1/2 = -6/2 + 1/2 = -5/2.