Елена Малышко
СИ
Сергей Илюхин
по частям
Андрей Шушлебин
Интеграл: S (x * e^3x * dx)
Интегрируем по частям.
= 1/3 * x * e^3x - S (1/3 * e^3x * dx) = 1/3 * x * e^3x - 1/9 * e^3x = 1/9 * e^3x * (3x - 1
СФ
Сергей Федоров
We'll integrate by parts. For this reason, we'll consider the formula:
Int udv = u*v - Int vdu (*)
We'll put u = x. (1)
We'll differentiate both sides:
du = dx (2)
We'll put dv = e^3x (3)
We'll integrate both sides:
Int dv = Int e^3x dx
v = e^3x/3 (4)
We'll substitute (1) , (2) , (3) and (4) in (*):
Int udv = x*e^3x/3 - Int (e^3x/3)dx
Int (x*e^3x)dx = x*e^3x/3 - e^3x/9 + C
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