So sanh a va b :
a=\(\sqrt{50+2}\)
b=\(\sqrt{50}+\sqrt{2}\)
So sánh
\(\sqrt{50+2}va\sqrt{50}+\sqrt{2}\)
\(\sqrt{63-27}va\sqrt{63}-\sqrt{27}\)
So sanh:
a, \(2-2\sqrt{3}\) va \(4-\sqrt{15}\)
b, \(\sqrt{11}+2\) va \(3+\sqrt{3}\)
a) \(2-2\sqrt{3}\) và \(4-\sqrt{15}\)
Giả sử : \(2-2\sqrt{3}\ge4-\sqrt{15}\)
⇔ \(\sqrt{15}-2\sqrt{3}\ge2\)
⇔ \(\left(\sqrt{15}-2\sqrt{3}\right)^2\ge2^2\)
⇔ 15 - \(12\sqrt{5}+12\) ≥ 4
⇔ 27 -4 ≥ \(12\sqrt{5}\)
⇔ 23 ≥ \(12\sqrt{5}\)
⇔ \(23^2\) ≥ \(\left(12\sqrt{5}\right)^2\)
⇔ 529 ≥ 720 (sai)
Vậy 2 - \(2\sqrt{3}< 4-\sqrt{15}\)
b) \(\sqrt{11}+2\) và \(3+\sqrt{3}\)
Giả sử : \(\sqrt{11}+2\le3+\sqrt{3}\)
⇔ \(\sqrt{11}-\sqrt{3}\le1\)
⇔ \(\left(\sqrt{11}-\sqrt{3}\right)^2\le1\)
⇔ 14 - \(2\sqrt{33}\) ≤ 1
⇔ 13 ≤ \(2\sqrt{33}\)
⇔ \(13^2\le\left(2\sqrt{33}\right)^2\)
⇔ 169 ≤ 132 (sai)
Vậy \(\sqrt{11}+2\ge3+\sqrt{3}\)
So sanh :
A=\(\sqrt[3]{2017}+\sqrt[3]{2019}\) va B=\(2\sqrt[3]{2018}\)
so sanh : A=\(\sqrt{11+\sqrt{96}}\) va B=\(\frac{2\sqrt{2}}{1+\sqrt{2}-\sqrt{3}}\)
\(A=\sqrt{11+\sqrt{96}}>B=\frac{2\sqrt{2}}{1+\sqrt{2}-\sqrt{3}}\)
Đã làm: https://olm.vn/hoi-dap/detail/223607632837.html
1`)So Sanh
a)\(\sqrt{24}+\sqrt{45}\) va 12
b)\(\sqrt{37}-\sqrt{15}\)va 2
giup mk voi nhe
a,Ta có:
\(\left(\sqrt{24}+\sqrt{45}\right)^2=24+45=69\)
\(12^2=144\)
Do 69<144 nên ...
b,tương tự ý a
a ) Ta co \(\sqrt{24}+\sqrt{45}< \sqrt{25}+\sqrt{49}=5+7=12\)
vay \(\sqrt{24}+\sqrt{45}< 12\)
b)ta co \(\sqrt{37}-\sqrt{15}>\sqrt{4}-\sqrt{0}=2-0=2\)
vay \(\sqrt{37}-\sqrt{15}>2\)
So sanh:
a, \(\sqrt{\dfrac{35}{34}}\) va \(\sqrt{\dfrac{71}{70}}\)
b, \(4\sqrt{5}-3\sqrt{2}\) va 5
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Giup minh voi !!! Khôi Bùi,DƯƠNG PHAN KHÁNH DƯƠNG, Phùng Khánh Linh, Nhã Doanh, hattori heiji, Phạm Hoàng Giang, Dũng Nguyễn, ...
so sanh
a) 2^90 va 5^36
b) 99^200 va 9999^100
c) 2^150 va 3^100
d) \(\sqrt{26+2}\) va \(\sqrt{26}\)+ \(\sqrt{2}\)
so sanh x va y biet
a) x=\(2\sqrt{7}\)va y=\(3\sqrt{3}\)
b) x=\(6\sqrt{2}\)va y=\(5\sqrt{3}\)
c) x=\(\sqrt{31}-\sqrt{33}\) va y=\(6-\sqrt{11}\)
So sánh 2 căn bậc sau:
a)\(_{\sqrt{27}}\) +\(\sqrt{12}\) với 8
b)\(\sqrt{50+2}\) với \(\sqrt{50}\) +\(\sqrt{2}\)
a) \(\sqrt{27}+\sqrt{12}>\sqrt{25}+\sqrt{9}=5+3=8\)
\(\Rightarrow\sqrt{27}+\sqrt{12}>8\)
b) \(\sqrt{50+2}=\sqrt{52}< \sqrt{64}=8\)
\(\sqrt{50}+\sqrt{2}>\sqrt{49}+\sqrt{1}=7+1=8\)
=> \(\sqrt{50+2}< 8< \sqrt{50}+\sqrt{2}\)
\(\Rightarrow\sqrt{50+2}< \sqrt{50}+\sqrt{2}\)