Behrouz Maleki

### Answers (381)

 37 Evaluate $\frac{0!}{4!}+\frac{1!}{5!}+\frac{2!}{6!}+\frac{3!}{7!}+\frac{4!}{8!}+\cdots$ 30 The sum of series with natural logarithm: $\sum_{n=1}^\infty \ln\left(\frac{n(n+2)}{(n+1)^2}\right)$ 28 Evaluate $\sqrt[2]{2} \cdot \sqrt[4]{4}\cdot \sqrt[8]{8}\cdot \dots$ 14 Why is $10^k - 1$ divisible by $9$? 13 If $f:X\rightarrow Y$ and $V\subseteq Y$, does there exist $U\subseteq X$ such that $f(U)=V$?

### Reputation (10,422)

 +10 Green's Theorem with change of variables +10 Evaluate $\iiint_V zdV$, V is volume bounded below by cone $x^2+y^2 = z^2$ and above by sphere$x^2+y^2+z^2=1$,lying on positive side of y-axis. +10 Why is $10^k - 1$ divisible by $9$? +10 Minimum of f(x,y,z)

### Questions (2)

 7 Inequality with a rational polynomial 2 How can we find minimum of $f(x,y,z)?$

### Tags (168)

 219 calculus × 82 49 trigonometry × 22 161 integration × 86 42 probability × 32 124 sequences-and-series × 26 39 algebra-precalculus × 14 80 definite-integrals × 31 37 factorial 62 stochastic-processes × 28 35 linear-algebra × 13

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