(2) (int )_(-infty )^+infty dfrac (dx)({x)^2+2x+2}

(int )_(-infty )^+infty dfrac (dx)({x)^2+2x+2}..

(int )_(-infty )^+infty (x)^2(e)^-a(x^2)dx=dfrac (1)(2)sqrt (dfrac {pi )({a)^3}}

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[题目]-|||-(int )_(2)^+infty dfrac (dx)((x+7)sqrt {x-2)}= __

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17 (int )_(-2)^0dfrac ((x+2)dx)({x)^2+2x+2}