So sánh \(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}...+\frac{1}{\sqrt{100}}\) và 10
So sánh:
\(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+.....+\frac{1}{\sqrt{100}}\) và 10
Ta có
\(\frac{1}{\sqrt{1}}>\frac{1}{\sqrt{100}}=\frac{1}{10}\)
\(\frac{1}{\sqrt{2}}>\frac{1}{\sqrt{100}}=\frac{1}{10}\)
........................................
\(\frac{1}{\sqrt{99}}>\frac{1}{\sqrt{100}}=\frac{1}{10}\)
=> \(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+....+\frac{1}{\sqrt{99}}+\frac{1}{\sqrt{100}}>\frac{1}{10}+\frac{1}{10}+...+\frac{1}{10}\)(100 số\(\frac{1}{10}\)) >10
Cho \(M=\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+...+\frac{1}{\sqrt{100}}.\)So sánh M với 10
\(\frac{1}{\sqrt{1}}>\frac{1}{\sqrt{10}};\frac{1}{\sqrt{2}}>\frac{1}{\sqrt{10}};...;\frac{1}{\sqrt{9}}>\frac{1}{\sqrt{10}};\frac{1}{\sqrt{10}}=\frac{1}{\sqrt{10}}\)
=>M>10
So sánh : \(A=\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+...+\frac{1}{\sqrt{100}}\) và B = 100
Hình như bạn hơi nhầm đề bài . Nếu B là 10 thì mình biết .
Nhận thấy : \(\frac{1}{\sqrt{1}}\)>\(\frac{1}{\sqrt{100}}\); \(\frac{1}{\sqrt{2}}\)>\(\frac{1}{\sqrt{100}}\);...: \(\frac{1}{\sqrt{100}}\)=\(\frac{1}{\sqrt{100}}\)
<=> A= \(\frac{1}{\sqrt{1}}\)+\(\frac{1}{\sqrt{2}}\)+\(\frac{1}{\sqrt{3}}\)+...+\(\frac{1}{\sqrt{100}}\)>\(\frac{1}{\sqrt{100}}\)+\(\frac{1}{\sqrt{100}}\)+...+\(\frac{1}{\sqrt{100}}\)( 100 số \(\frac{1}{\sqrt{100}}\))
Hay : A > \(\frac{1}{\sqrt{100}}\).100
<=> A > 10
<=> A>B
Nếu không đúng mong bạn thông cảm nhé !!
so sánh
\(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+\frac{1}{\sqrt{4}}+...+\frac{1}{\sqrt{100}}\)\(\)va \(10\)
\(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+.....+\frac{1}{\sqrt{100}}>\frac{1}{\sqrt{100}}+\frac{1}{\sqrt{100}}+....+\frac{1}{\sqrt{100}}\)
\(\Leftrightarrow\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+....+\frac{1}{\sqrt{100}}>100.\frac{1}{\sqrt{100}}=10.\)
Cho A = \(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+...+\frac{1}{\sqrt{100}}\)
So sánh A với 10.
So sánh A với 10 biết\(A=\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+...+\frac{1}{\sqrt{100}}\)
a) so sánh
\(\sqrt{17}+\sqrt{26}+1\) và \(\sqrt{99}\)
b) CMR
\(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+...+\frac{1}{\sqrt{100}}>10\)
a)Ta có:\(\sqrt{17}>\sqrt{16}\)
\(\sqrt{26}>\sqrt{25}\)
\(\implies\) \(\sqrt{17}+\sqrt{26}>\sqrt{16}+\sqrt{25}\)
\(\implies\) \(\sqrt{17}+\sqrt{26}+1>\sqrt{16}+\sqrt{25}+1=4+5+1=10\)
Mà \(\sqrt{100}=10\) \(\implies\) \(\sqrt{17}+\sqrt{26}+1>\sqrt{100}\)
Mà \(\sqrt{100}>\sqrt{99}\) \(\implies\) \(\sqrt{17}+\sqrt{26}+1>\sqrt{99}\)
b)Ta có:\(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+....+\frac{1}{\sqrt{100}}>\frac{1}{\sqrt{100}}+\frac{1}{\sqrt{100}}+...+\frac{1}{\sqrt{100}}=100.\frac{1}{\sqrt{100}}\)
\(\implies\) \(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+....+\frac{1}{\sqrt{100}}>\frac{1}{10}.100=10\)
\(\implies\) \(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+....+\frac{1}{\sqrt{100}}>10\left(đpcm\right)\)
So sánh
A=\(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+.......+\frac{1}{\sqrt{100}}\) và 10
Giải chi tiết giùm nha Cảm ơn trước nhiều
\(\frac{1}{\sqrt{1}}>\frac{1}{\sqrt{10}};\frac{1}{\sqrt{2}}>\frac{1}{\sqrt{10}};...;\frac{1}{\sqrt{99}}>\frac{1}{\sqrt{100}};\frac{1}{\sqrt{100}}=\frac{1}{\sqrt{100}}\)
\(\Rightarrow A>\frac{100.1}{\sqrt{100}}=\frac{100}{10}=10\)
Vậy A > 10
ta có \(\frac{1}{\sqrt{1}}>\frac{1}{10}\)
\(\frac{1}{\sqrt{2}}>\frac{1}{10}\)
..............................
\(\frac{1}{\sqrt{99}}>\frac{1}{10}\)
\(\frac{1}{\sqrt{100}}=\frac{1}{10}\)
\(\Rightarrow\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+...+\frac{1}{\sqrt{100}}>\frac{1}{10}+\frac{1}{10}+...+\frac{1}{10}\)(có 100 số 1/10)
\(\Rightarrow A>\frac{100}{10}=10\)
so sánh $\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+...+\frac{1}{\sqrt{100}}$ với 10. Trình bày cách giải nha bạn