sum from n=0 to infinity of n!*x^n

解答

n = 0 \sum \infty n! \cdot x^{n}

收敛半径为 0, 收敛区间为 x = 0

求解步骤

n = 0 \sum \infty n! x^{n}

使用比值审敛法计算收敛区间

收敛半径为 0, 收敛区间为 x = 0

d er i v a t i v e f (x) = tan (x) cot (x) sin (x)

\frac{d ^{2}}{d x ^{2}} (\frac{1 - 2 x}{1 + 2 x})

\int_{2}^{6} 1 + \frac{1}{4} x^{1} d x

t an g e n t f (x) = 3 x^{2} - 3 x + 4

\frac{\partial}{\partial x} (t^{4} + x^{3})