Question

[Mai Anh Nguyen]

a)Điền dấu >;<;= thích hợp vào chỗ chấm:

\(\frac{1}{a.\left(a+1\right)}\frac{1}{a}......\frac{1}{\left(a+1\right)}\)

Answer 1

[✎﹏ミ★꧁༺вєѕт↭ℓαυяιєℓ↭νи༻꧂★ミ.༻(Trưở...]

điền dấu <

Answer 2

[Member lỗi thời :&gt;&gt;]

\(\frac{1}{a.\left(a+1\right)}.\frac{1}{a}.......\frac{1}{\left(a+1\right)}\left(a ∈ N\right)\)

\(\text{Ta có :}\frac{1}{a.\left(a+1\right)}.\frac{1}{a}=\frac{1}{a.\left[a.\left(a+1\right)\right]}\)

\(=\frac{1}{a.\left(a^2+a\right)}=\frac{1}{a^3+a^2}\)

\(\text{Vì }a^2.\left(a+1\right)>\left(a+1\right)\Rightarrow\frac{1}{a^2.\left(a+1\right)}< \frac{1}{\left(a+1\right)}\)