,
u v .
. , , . u , , dv , .
,
1.
, , ,
P(x) , - , u = P(x), dv.
2.
, , ,
,
(x)dx = dv, u.
3.
,
u eax sin bx ( cos bx).
13. .
. u = x, dv = ,
du = dx, v = = , . . v = -cos x.
,
.
14.
. dv = x2dx, ln x = u,
v = , du =
.
15. I= .
. u = ex, dv = sin x dx,
du = exdx, v = .
I = -excos x + .
, u = ex, dv = cos x dx, du = exdx v = I = -excos x + (xsin x - ) = -excos x + exsin x - I.
, . , I.
2I = -excos x + exsin x,
I = .
f(x) [a; b], a < b. n = x0 < x1 < x2 < < < xi-1 < xi < < xn = b. [xi-1; xi] x (xi-1 £ x £ xi) Dxi = xi - xi-1 .
f(x) [a; b].
l : l = mx{Dxi}.
1. f(x) [a; b] l0, ..
= .
a b .
f(x) [a; b], .
S , f(x), x = a x = b, . . S = . .