`a, sqrt 49 > 6`
`b, -sqrt 2 > - sqrt 3`
`c, sqrt (5/16) < sqrt (11/16)`
`d, -sqrt 1000 < sqrt 4`
`e, sqrt(2 3/4) > sqrt (13/12)`
`f, sqrt(15/28) < sqrt (9/14)`
`g, sqrt 31 > 5`
`h, sqrt (25/49) > 5/8`
Câu 1:
a: \(\sqrt{49}>\sqrt{36}=6\)
b: \(\sqrt{2}>\sqrt{3}\)
nên \(-\sqrt{2}>-\sqrt{3}\)
c: \(5< 11\Leftrightarrow\sqrt{\dfrac{5}{16}}< \sqrt{\dfrac{11}{16}}\)
d: \(-\sqrt{1000}< 0< \sqrt{4}\)
a) Có: \(\sqrt{49}=7>6\)
b) Có: \(-\sqrt{2}>-\sqrt{3}\) vì \(-2>-3\)
c) Có: \(5< 11\Rightarrow\sqrt{\dfrac{5}{16}}< \sqrt{\dfrac{11}{16}}\)
d) Có: \(-\sqrt{1000}< 0< \sqrt{4}=2\)
Bài 1
a) \(\sqrt{49}=7\)
Do 7 > 6
\(\Rightarrow\sqrt{49}>6\)
b) \(2< 3\)
\(\Rightarrow\sqrt{2}< \sqrt{3}\)
\(\Rightarrow-\sqrt{2}< -\sqrt{3}\)
c) \(\sqrt{\dfrac{5}{16}}=\dfrac{\sqrt{5}}{4}\)
\(\sqrt{\dfrac{11}{16}}=\dfrac{\sqrt{11}}{4}\)
Do 5 < 11 \(\Rightarrow\sqrt{5}< \sqrt{11}\)
\(\Rightarrow\dfrac{\sqrt{5}}{4}< \dfrac{\sqrt{11}}{4}\)
\(\Rightarrow\sqrt{\dfrac{5}{16}}< \sqrt{\dfrac{11}{16}}\)
d) \(-\sqrt{1000}< 0\)
\(0< \sqrt{4}\)
\(\Rightarrow-\sqrt{1000}< \sqrt{4}\)
e) \(\sqrt{2\dfrac{3}{4}}=\sqrt{\dfrac{11}{4}}\)
\(\dfrac{11}{4}=\dfrac{33}{12}\)
\(\dfrac{33}{12}>\dfrac{11}{12}\)
\(\Rightarrow\sqrt{\dfrac{33}{12}}>\sqrt{\dfrac{13}{12}}\)
\(\Rightarrow\sqrt{\dfrac{11}{4}}>\sqrt{\dfrac{13}{12}}\)
\(\Rightarrow\sqrt{2\dfrac{3}{4}}>\sqrt{\dfrac{13}{12}}\)
f) \(\dfrac{9}{14}=\dfrac{18}{28}\)
\(\dfrac{15}{28}< \dfrac{18}{28}\)
\(\Rightarrow\sqrt{\dfrac{15}{28}}< \sqrt{\dfrac{18}{28}}\)
\(\Rightarrow\sqrt{\dfrac{15}{28}}< \sqrt{\dfrac{9}{14}}\)
g) \(5=\sqrt{25}\)
\(31>25\)
\(\Rightarrow\sqrt{31}>\sqrt{25}\)
\(\Rightarrow\sqrt{31}>5\)
h) \(\sqrt{\dfrac{25}{49}}=\dfrac{5}{7}\)
\(7< 8\)
\(\Rightarrow\dfrac{5}{7}>\dfrac{5}{8}\)
\(\Rightarrow\sqrt{\dfrac{25}{49}}>\dfrac{5}{8}\)
