Begin2.DVI

(Ben Green) #1
Appendix C

Table of Integrals
Indefinite Integrals

General Integration Properties



  1. IfdFdx(x)=f(x), then



f(x)dx=F(x) +C


  1. If



f(x)dx=F(x) +C, then the substitutionx=g(u)gives


f(g(u))g′(u)du=F(g(u)) +C

For example, if

∫ dx
x^2 +β^2 =

1
βtan

− 1 x
β+C, then

∫ du
(u+α)^2 +β^2 =

1
βtan

− 1 u+α
β +C


  1. Integration by parts. Ifv 1 (x) =



v(x)dx, then


u(x)v(x)dx=u(x)v 1 (x)−


u′(x)v 1 (x)dx


  1. Repeated integration by parts or generalized integration by parts.
    Ifv 1 (x) =



v(x)dx, v 2 (x) =


v 1 (x)dx,... , vn(x) =


vn− 1 (x)dx, then

u(x)v(x)dx=uv 1 −u′v 2 +u′′v 3 −u′′′v 4 +···+ (−1)n−^1 un−^1 vn+ (−1)n


u(n)(x)vn(x)dx


  1. Iff−^1 (x)is the inverse function off(x)and if



f(x)dxis known, then

f−^1 (x)dx=zf(z)−


f(z)dz, where z=f−^1 (x)


  1. Fundamental theorem of calculus.
    ∫If the indefinite integral off(x)is known, say
    f(x)dx=F(x) +C, then the definite integral


∫b

a

dA=

∫b

a

f(x)dx=F(x)]ba=F(b)−F(a)

represents the area bounded by the x-axis, the curve
y = f(x)and the linesx=aandx=b.


  1. Inequalities.
    (i) Iff(x)≤g(x)for allx∈(a, b), then


∫b

a

f(x)dx≤

∫b

a

g(x)dx
(ii) If|f(x)≤M|for allx∈(a, b)and

∫b
af(x)dxexists, then
∣∣
∣∣

∫b

a

f(x)dx

∣∣
∣∣
∣≤

∫b

a

f(x)dx≤M(b−a)

Appendix C
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