Question

chứng tỏ rằng: A= \(\frac{\text{1}}{2\text{1}}\) +\(\frac{2}{3\text{1}}\) +...+ \(\frac{20\text{1}3}{20\text{1}4}\) < 1

Answer 1

lon hon 1 nha ban

Answer 2

sửa lại đề : Chứng tỏ rằng : A = \(\frac{1}{2!}+\frac{2}{3!}+...+\frac{2013}{2014!}< 1\)

bài làm

A = \(\frac{1}{2!}+\frac{2}{3!}+...+\frac{2013}{2014!}\)

A = \(\frac{2-1}{2!}+\frac{3-1}{3!}+...+\frac{2014-1}{2014!}\)

A = \(1-\frac{1}{2!}+\frac{3}{3!}-\frac{1}{3!}+...+\frac{2014}{2014!}-\frac{1}{2014!}\)

A = \(1-\frac{1}{2!}+\frac{1}{2!}-\frac{1}{3!}+...+\frac{1}{2013!}-\frac{1}{2014!}\)

A = \(1-\frac{1}{2014!}< 1\)

Answer 3

lớn hơn 1 nha.

Answer 4

bé hơn 1 mới đúng