sum from n=3 to infinity of (3^n)/(11^n)

解答

n = 3 \sum \infty \frac{3 ^{n}}{1 1 ^{n}}

收敛

求解步骤

n = 3 \sum \infty \frac{3 ^{n}}{1 1 ^{n}}

使用级数比值审敛法:

收敛

= 收敛

\int \frac{y ^{2} - 49}{y} d y

\int sin (12 x) cos (5 x) d x

\int_{- \infty}^{0} \frac{1}{5 - 4 x} d x

\frac{d}{d x} (ln (13 x) + 13)

\frac{d y}{d x} = \frac{y ^{2} + 3 x x ^{2} + y ^{2}}{x y}