We'll write the definite integral of
I(n):
I(n) = Int x^n
dx/(x^2+2010^2)
We'll multiply I(n) by
2010^2:
2010^2I(n) = Int 2010^2*x^n dx/(x^2+2010^2)
(1)
We'll write the definite integral of
I(n+2):
I(n+2) = Int x^(n+2) dx/(x^2+2010^2)
(2)
We'll apply the property of integral to be
additive:
(1) + (2) = Int [x^(n+2) +
2010^2*x^n]dx/(x^2+2010^2)
Well factorize by
x^n:
Int [x^n(x^2 +
2010^2)]dx/(x^2+2010^2)
We'll simplify by (x^2+2010^2) and
we'll get:
Int x^n dx =
x^(n+1)/(n+1)
For x = 0 => 0^(n+1)/(n+1) =
0
For x = 1 =>
1/(n+1)
We'll apply
Leibniz-Newton:
Int x^n dx = F(1) -
F(0)
Int x^n dx =
1/(n+1)
I(n+2) + 2010^2I(n) = Int x^n dx
= 1/(n+1) q.e.d.
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