微分及び積分(1/2)

02_016_017.QX 08.6.8 2:50 PM ページ 16
微分及び積分(1/2)
微 分 法
基本公式
f´ (x)
f (x)
2
公
式
演 算 公 式
1
(1) f (x)dx=F (x) のとき f (ax+b)dx= F (ax+b)
a
f´ (x)
f (x)
(2) cf (x)dx=c f (x)dx
c (定数)
0
x a (定数)
sin x
cos x
cos x
−sin x
(3) { f (x)⫾g(x)} dx= f (x)dx⫾g(x) dx
tan x
sec 2 x
cot x
−cosec2 x
(4) 部分積分法 f (x)g´ (x)dx= f (x)g(x)− f´(x)g(x)dx
sec x
sec x tan x
cosec x
−cosec x cot x
ex
ex
a x(a>0)
a x log a
log a x
1
x 1og a
1
x
log | x |
1
1−x 2
1
1+x 2
sin−1x
tan−1x
sec−1x
|x|
ax a−1
−1
1−x 2
−1
1+x 2
cos−1x
cot−1x
1
x 2−1
特に f (x)dx=xf(x)− xf´(x)dx
cosce−1x
|x|
主要な原始関数の表
f (x)dx
f (x)
−1
x 2−1
sinh x
cosh x
cosh x
sinh x
tanh x
sech2 x
coth x
−cosech 2 x
1
(a2−x 2 )2
x
(a2−x 2 )2
x
1
+
2a2(a2−x 2)
2a3
|
log
a+x
a−x
|
1
2(a2−x 2 )
演 算 公 式
(1) (c f (x) )´ = c f´ (x) (2) ( f (x)⫾g (x) )´ = f´ (x)⫾g´ (x)
(3) ( f (x) g (x) )´ = f´ (x) g (x) + f (x) g´ (x)
f(x) ´
f´ (x) g (x) − f (x) g´ (x)
(4) =
g(x)
{ g (x)}2
−g´ (x)
1 ´
特に =
{ g (x)}2
g (x)
(
1
(a2+x 2 )2
x
1
+
2a2(a2+x 2)
2a3
x
(a2+x 2 )2
−
tan−1
x
a
)
(
)
(5) 合成関数 y = f ( g (x) ) のとき g (x) = z において
dy
dy
= f´ (z) g´ (x) =
dz
dx
1
ax 2+bx+c
dz
dx
特に ( f (cx) )´ = c´f (cx), ( log | f x)|´) = f ´ (x) / f (x),
( e f (x))´ = e
f (x)
D=b2−4ac
f´ (x) など
dy
dx
(6) = 1 / (逆関数)
dx
dy
1
x 3⫾a3
1
2(a2+x 2 )
1 log
D
2ax+b − D
2ax+b + D
(D>0)
2 2ax+b
tan−1
(D<0)
−D
−D
1
(x⫾a)2
1 2x⫿a
tan−1
log ⫾
6a2
x 2⫿ax+a2
3a2
3a
(7) 対数微分法 y = ( f1 (x) )a ( f2 (x) )b … ( fk (x) )l
のとき log | y |= alog | f1 (x)|+ blog | f2 (x)|+…+ l log | fk (x)|
y´
f´ (x)
f´ (x)
として = a 1 + b 2 +…+ l
y
f1 (x)
f2 (x)
基本公式(積分定数は略す)
xa
x a+1
(a≠−1)
a+1
1/x
log | x |
ex
ex
ax
a x /log a
D=b2−4ac
f (x)dx
f (x)
cot x
1
a2−x 2
1
x 2+A
a2−x 2
log x
x (log x−1)
loga x
x (log x−1) / log a
cos x
sin x
−cos x
1
a2−x2
sin x
␸(x)=ax 2+bx+c
不 定 積 分
f (x)dx
f (x)
log | sin x |
x
sin−1 (a>0)
a
log | x+ x2+A
(
(a>0)
x 2+A
|
1
2
2
2
−1
2 x a −x +a sinx
a
)
1
(x+ x 2+A
2
+Alog | x+ x2+A)| )
1
a+x
log
2a
a−x
sec2 x
tan x
1
a2+x2
1
x
−1
a tan a
cosec2 x
−cot x
sinh x
cosh x
tan x
−log | cos x |
cosh x
sinh x
16
1 ax 2+bx+c
f´k (x)
fk (x)
1
log | 2ax+b +2 a
a
−1 −1
sin
−a
␸(x)
2ax+b b2−4ac
1 2ax−x 2
⫾sin−1
1 2ax+x 2
log | x+a + 2ax+x 2
1 (x−a)(b−x)
⫾sin−1
x−a
a
|
(a>0)
(a<0,D>0)
(a⭵0)
2x−(a+b)
a−b
|
(a⭵b)
ax 2+bx+c
2ax+b
4a
␸(x) −
D
8a a
␸(x)=ax 2+bx+c
2ax+b
4a
␸(x) +
2ax+b
D
sin−1
(a<0,
D
8a −a
D>0)
D=b2−4ac
2ax−x 2
x−a
2
2ax−x 2 +
log | 2ax+b +2 a
a2
x−a
sin−1
a
2
␸(x)
|
(a>0)