F (x) f (x) (a; b), x∈(a; b) F′ (x) = f (x).
, x 2 x 3/3.
F (x) dF (x) = f (x) dx, F (x) f (x), .
, .
1. F (x) f (x) (a; b), F (x) + C, C , f (x) (a; b).
: (F + C) ′ = F′ + C′ = f + 0 = f
F + C f.
2, .
g (x) (a; b), g′ (x) = 0.
: g (x) = C, : g′ (x) = C′ = 0 (, , C ).
g′ (x) = 0 x ∈(a; b), g (x) = C (a; b).
: g′ (x) = 0 (a; b). x 1∈(a; b). x ∈(a; b) g (x) g (x 1) = g′ (ξ)(x x 1). ξ ∈(x; x 1), x x 1 (a; b), g′ (ξ) = 0, , g (x) g (x 1)=0, g (x) = g (x 1)= const.
2. F (x) f (x) (a; b), G (x) f (x) (a; b), G = F + C, C .
: G F: (G F) ′ = G′ F′ = f f = 0. : G F = C, C , G = F + C.
f (x) (a; b) ∫ f (x) dx. F (x) f (x), ∫ f (x) dx = F (x) + C, C .
.
, F′ (x) = f (x) ∫ f (x) dx = F (x) + C . :
5.1.
1) ∫ dx = x + C | 7) ∫ cos x dx = sin x + C |
2) ∫ xαdx =(α ≠1) | 8) |
3) | 9) |
4) ∫ exdx = ex + C | 10) |
5) ∫ axdx = ax log ae + C (α ≠1) | 11) |
6) ∫ sin x dx=- cos x + C | 12) |
:
5.2.
1) (∫ f (x) dx) ′=f (x); | 4) ∫ d f (x)= f (x)+ C; |
2) ∫ f′ (x) dx = f (x)+ C; | 5) ∫ kf (x) dx=k ∫ f (x) dx; |
3) d ∫ f (x) dx= f (x) dx; | 6) ∫(f (x)+ g (x)) dx= ∫ f (x) dx +∫ g (x) dx; |
7. ∫ f (x) dx = F (x) + C, ∫ f (ax+b) dx = (a ≠ 0). |
.
|
|
f (x) , φ (t) φ′ (t), ∫ f (φ (t)) φ′ (t) dt = ∫ f(x) dx, x = φ (t).
, .
. 1. I = ∫ cos(t 3) t 2 dt. t 3 = x, dx = 3 t 2 dt t 2 dt = dx/ 3.
.
. ln t = x, dx = dt/t.
. x = cos t, dx = - sin t dt,
.
. x = sin t, dx = cos dt,
.
u (x) v (x) . (uv) ′ = u′v + v′u
∫ (uv) ′dx = ∫ (u′v + v′u) dx = ∫ u′v dx + ∫ v′u dx
∫ uv′ dx = uv ∫ u′v dx.
, : ∫ u (x) dv (x) = u (x) v (x) ∫ v (x) du (x)
.
. 1. I = ∫ x cos x dx. u = x; dv = cos x dx, du = dx; v = sin x. : I = x sin x ∫ sin x dx = x sin x + cos x + C. I = ∫ (x2 3 x + 2) e5xdx. x2 3 x + 2 = u; e5xdx = dv.
du = (2 x 3) dx;..
, 2 x - 3 = u; e5xdx = dv. : du = 2 dx;, :
;
, 12:
.
: , A B.
. :.
. , , . .