Question

$1 + \frac{2^{4}}{2!} + \frac{3^{4}}{3!} + \frac{4^{4}}{4!} + .....\infty =$

• A. $5e$
• B. $e$
• C. $15e$
• D. $2e$

Answer 1

Answer: (C)

$15e$

Answer 2

$\frac{4}{1.3} - \frac{6}{2.4} + \frac{12}{5.7} - \frac{14}{6.8} + .....\infty =$

$\log_{e}3$

$\log_{e}2$

$2\log_{e}2$

$\log_{e}x - \log_{e}(x - 1) =$

=$\frac{1}{x} - \frac{1}{2x^{2}} + \frac{1}{3x^{3}} - .....\infty$

= $\frac{1}{x} + \frac{1}{2x^{2}} + \frac{1}{3x^{3}} + .....\infty$.