SO SÁNH :
\(\sqrt{16}+\sqrt{4}+\sqrt{10}+\sqrt{10^2}\)với\(\sqrt{100}+\sqrt{100}+\sqrt{25}\)\(+\sqrt{1000}\)
so sánh \(\dfrac{1}{\sqrt{1}}+\dfrac{1}{\sqrt{2}}+\dfrac{1}{\sqrt{3}}+....+\dfrac{1}{\sqrt{100}}\)với 10
\(\dfrac{1}{\sqrt{1}}+\dfrac{1}{\sqrt{2}}+\dfrac{1}{\sqrt{3}}+...+\dfrac{1}{\sqrt{100}}>\dfrac{1}{\sqrt{100}}+\dfrac{1}{\sqrt{100}}+\dfrac{1}{\sqrt{100}}+...+\dfrac{1}{\sqrt{100}}\)
(100 số số hạng)
\(\Rightarrow\dfrac{1}{\sqrt{1}}+\dfrac{1}{\sqrt{2}}+\dfrac{1}{\sqrt{3}}+...+\dfrac{1}{\sqrt{100}}>\dfrac{100}{\sqrt{100}}=\dfrac{100}{10}=10\)
so sánh \(\dfrac{\sqrt{21}-\sqrt{13}}{35-2\sqrt{273}}+\dfrac{\sqrt{10}-\sqrt{5}}{16-10\sqrt{2}}\)với 1
so sánh các số sau: a,\(0,5\sqrt{100}-\sqrt{\frac{4}{25}}và\left(\sqrt{1\frac{1}{9}-\sqrt{\frac{9}{16}}}\right):5\)
\(0,5\sqrt{100}-\sqrt{\frac{4}{25}}=0,5.10-\frac{\sqrt{4}}{\sqrt{25}}=5-\frac{2}{5}=\frac{23}{5}=\frac{138}{30}\)
\(\left(\sqrt{1\frac{1}{9}-\sqrt{\frac{9}{16}}}\right):5=\left(\sqrt{\frac{10}{9}-\frac{3}{4}}\right):5=\sqrt{\frac{13}{36}}:5=\frac{\sqrt{13}}{6}:5=\frac{\sqrt{13}}{30}\)
Vì 13 < 138 nên \(\sqrt{13}< 138\Rightarrow\frac{\sqrt{13}}{30}< \frac{138}{30}\)
Vậy \(0,5\sqrt{100}-\sqrt{\frac{4}{25}}>\left(\sqrt{1\frac{1}{9}-\sqrt{\frac{9}{16}}}\right):5\).
So sánh:
a)\(A=\sqrt[]{21}+\sqrt{42}+\sqrt{63}\)
\(B=\sqrt{1}+\sqrt{2}+\sqrt{3}+\sqrt{20}+\sqrt{40}+\sqrt{60}\)
b)\(A=\left(1-\frac{1}{\sqrt{4}}\right)\left(1-\frac{1}{\sqrt{16}}\right)\left(1-\frac{1}{\sqrt{100}}\right)\)
\(B=\sqrt{0,1}\)
c) \(A=\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+...+\frac{1}{\sqrt{100}}\)
\(B=10\)
so sánh $\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+...+\frac{1}{\sqrt{100}}$ với 10. Trình bày cách giải nha bạn
So sánh các số sau:
a) \(0,5\sqrt{100}-\sqrt{\frac{4}{25}}v\text{à}\left(\sqrt{1\frac{1}{9}}-\sqrt{\frac{9}{16}}\right):5\)
b) \(\sqrt{25+9}v\text{à}\sqrt{25}+\sqrt{9}\)
\(0,5\sqrt{100}-\sqrt[]{\frac{4}{25}}va\left(\sqrt{\frac{10}{9}}-\sqrt{\frac{9}{16}}\right):5\)
so sanh
(1+1_1/4+1_1/2+1_3/4+2+2_1/4+2_1/2+2_3/4+......+4_3/4) : 23 tính nhanh !!!!! Ai nhanh mình kêu anh chị mình vào nha !! Mình cần gấp lắm !! Cảm ơn mọi người
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 \(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}...+\frac{1}{\sqrt{100}}\) và 10
Ta có: \(\frac{1}{\sqrt{1}}>\frac{1}{\sqrt{100}}\)
\(\frac{1}{\sqrt{2}}>\frac{1}{\sqrt{100}}\)
\(\frac{1}{\sqrt{3}}>\frac{1}{\sqrt{100}}\)
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\(\frac{1}{\sqrt{100}}=\frac{1}{\sqrt{100}}\)
\(\Rightarrow\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+...+\frac{1}{\sqrt{100}}>\frac{1}{\sqrt{100}}.100=\frac{100}{10}=10\)
Vậy \(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+...+\frac{1}{\sqrt{100}}>10\)