Sviluppi_McLaurin

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Alcuni sviluppi di McLaurin notevoli (si sottintende ovunque che i resti sono trascurabili per x 0) e x =1+ x + x 2 2! + x 3 3! + ··· + x n n! + o (x n ) = n k=0 x k k! + o (x n ) sinh x = x + x 3 3! + x 5 5! + ··· + x 2n+1 (2n + 1)! + ox 2n+2 = n k=0 x 2k+1 (2k + 1)! + ox 2n+2 cosh x =1+ x 2 2! + x 4 4! + ··· + x 2n (2n)! + ox 2n+1 = n k=0 x 2k (2k)! + ox 2n+2 tanh x = x 1 3 x 3 + 2 15 x 5 + ox 6 ln (1 + x) = x x 2 2 + x 3 3 x 4 4 + ··· +(1) n1 x n n + o (x n ) = n k=1 (1) k1 x k k + o (x n ) sin x = x x 3 3! + x 5 5! + ··· +(1) n x 2n+1 (2n + 1)! + ox 2n+2 = n k=0 (1) k x 2k+1 (2k + 1)! + ox 2n+2 cos x =1 x 2 2! + x 4 4! + ··· +(1) n x 2n (2n)! + ox 2n+1 = n k=0 (1) k x 2k (2k)! + ox 2n+1 tan x = x + 1 3 x 3 + 2 15 x 5 + ox 6 arcsin x = x + 1 6 x 3 + 3 40 x 5 + ··· + 1/2 n x 2n+1 2n +1 + ox 2n+2 = n k=0 1/2 k x 2k+1 2k +1 + ox 2n+2 arccos x = π 2 arcsin x arctan x = x x 3 3 + x 5 5 + ··· +(1) n x 2n+1 2n +1 + ox 2n+2 = n k=0 (1) k x 2k+1 2k +1 + ox 2n+2 (1 + x) α =1+ αx + α 2 x 2 + α 3 x 3 + ··· + α n x n + o (x n ) = n k=0 α k x k + o (x n ) 1 1+ x =1 x + x 2 x 3 + x 4 + ··· +(1) n x n + o (x n ) = n k=0 (1) k x k + o (x n ) 1 1 x =1+ x + x 2 + x 3 + x 4 + ··· + x n + o (x n ) = n k=0 x k + o (x n ) 1+ x =1+ 1 2 x 1 8 x 2 + 1 16 x 3 + ··· + 1/2 n x n + o (x n ) = n k=0 1/2 k x k + o (x n ) 1 1+ x =1 1 2 x + 3 8 x 2 5 16 x 3 + ··· + 1/2 n x n + o (x n ) = n k=0 1/2 k x k + o (x n ) 3 1+ x =1+ 1 3 x 1 9 x 2 + 5 81 x 3 + ··· + 1/3 n x n + o (x n ) = n k=0 1/3 k x k + o (x n ) 1 3 1+ x =1 1 3 x + 2 9 x 2 7 81 x 3 + ··· + 1/3 n x n + o (x n ) = n k=0 1/3 k x k + o (x n ) Si ricordi che α R si pone α 0 =1 e α n = n fattori α (α 1) ··· (α n + 1) n! se n 1.

description

x 2n+1 2n+1+o x 2n+2 = 1 1−x =1+x+x 2 +x 3 +x 4 +···+x n +o(x n ) = k x k +o(x n ) 3 x 3 +···+ α √1+x =1+1 2x− √1+x =1+1 3x− 1 8x 2 + 1 16x 3 +···+ 1/2 1 9x 2 + 5 81x 3 +···+ 1/3 x 2k+1 2k+1+o x 2n+2 x 2k+1 (2k+1)!+o x 2n+2 α(α−1)···(α−n+1) (−1) k x 2k+1 (2k+1)!+o x 2n+2 (−1) k x 2k+1 2k+1+o x 2n+2 x 2k (2k)!+o x 2n+2 3 8x 2 − 5 16x 3 +···+ −1/2 2 9x 2 − 7 81x 3 +···+ −1/3 (−1) k x 2k (2k)!+o x 2n+1 1 √1+x =1−1 2x+ 2!+

Transcript of Sviluppi_McLaurin

Page 1: Sviluppi_McLaurin

Alcuni sviluppi di McLaurin notevoli (si sottintende ovunque che i resti sono trascurabili per x→ 0)

ex = 1 + x+x2

2!+x3

3!+ · · ·+ x

n

n!+ o (xn) =

n

k=0

xk

k!+ o (xn)

sinhx = x+x3

3!+x5

5!+ · · ·+ x2n+1

(2n+ 1)!+ o x2n+2 =

n

k=0

x2k+1

(2k + 1)!+ o x2n+2

coshx = 1 +x2

2!+x4

4!+ · · ·+ x2n

(2n)!+ o x2n+1 =

n

k=0

x2k

(2k)!+ o x2n+2

tanhx = x− 13x3 +

2

15x5 + o x6

ln (1 + x) = x− x2

2+x3

3− x

4

4+ · · ·+ (−1)n−1 x

n

n+ o (xn) =

n

k=1

(−1)k−1 xk

k+ o (xn)

sinx = x− x3

3!+x5

5!+ · · ·+ (−1)n x2n+1

(2n+ 1)!+ o x2n+2 =

n

k=0

(−1)k x2k+1

(2k + 1)!+ o x2n+2

cosx = 1− x2

2!+x4

4!+ · · ·+ (−1)n x2n

(2n)!+ o x2n+1 =

n

k=0

(−1)k x2k

(2k)!+ o x2n+1

tanx = x+1

3x3 +

2

15x5 + o x6

arcsinx = x+1

6x3 +

3

40x5 + · · ·+ −1/2

n

x2n+1

2n+ 1+ o x2n+2 =

n

k=0

−1/2k

x2k+1

2k + 1+ o x2n+2

arccosx =π

2− arcsinx

arctanx = x− x3

3+x5

5+ · · ·+ (−1)n x

2n+1

2n+ 1+ o x2n+2 =

n

k=0

(−1)k x2k+1

2k + 1+ o x2n+2

(1 + x)α = 1 + αx+α

2x2 +

α

3x3 + · · ·+ α

nxn + o (xn) =

n

k=0

α

kxk + o (xn)

1

1 + x= 1− x+ x2 − x3 + x4 + · · ·+ (−1)n xn + o (xn) =

n

k=0

(−1)k xk + o (xn)

1

1− x = 1 + x+ x2 + x3 + x4 + · · ·+ xn + o (xn) =

n

k=0

xk + o (xn)

√1 + x = 1 +

1

2x− 1

8x2 +

1

16x3 + · · ·+ 1/2

nxn + o (xn) =

n

k=0

1/2

kxk + o (xn)

1√1 + x

= 1− 12x+

3

8x2 − 5

16x3 + · · ·+ −1/2

nxn + o (xn) =

n

k=0

−1/2k

xk + o (xn)

3√1 + x = 1 +

1

3x− 1

9x2 +

5

81x3 + · · ·+ 1/3

nxn + o (xn) =

n

k=0

1/3

kxk + o (xn)

13√1 + x

= 1− 13x+

2

9x2 − 7

81x3 + · · ·+ −1/3

nxn + o (xn) =

n

k=0

−1/3k

xk + o (xn)

Si ricordi che ∀α ∈ R si pone α

0= 1 e

α

n=

n fattori

α (α− 1) · · · (α− n+ 1)n! se n ≥ 1.