so sanh :
1 va \(\sqrt{3}-1\)
so sanh \(\sqrt{8}\)va \(\sqrt{5}\)+1
có \(\sqrt{8}\)<\(\sqrt{9}\)=3
\(\sqrt{5}\)+1>\(\sqrt{4}\)+1=3
suy ra \(\sqrt{5}\)+1>\(\sqrt{8}\)
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
bai 1 : tinh
\(\sqrt{49}\); \(\sqrt{-49}\) ; \(\sqrt{0,01}\)
bai 2 : so sanh
a,15 va \(\sqrt{235}\)
b,\(\sqrt{7}\)+ \(\sqrt{15}\)va 7
bai 3 ; tinh hop ly
A = 7,3.10,5-7,3.15+2,7.10,5-15.2,7
bai 4 : so sanh
a, 1,(05) va 0,(31)
b, 3,0(21) va 3,021
c,0,001 va 0,(001)
d,1,(31) va 1,(313)
bai 4 so sanh cac so thuc
\(\frac{4}{9}va\)0,4(5)
\(\sqrt[2]{3}va\sqrt[3]{2}\)
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 \(A=\sqrt[1995]{1996!}\) va \(B=1+\sqrt[1995]{1995!}\)
Ta có :1996! = 1.2.3 . ... . 1995 . 1996
: 1995! = 1.2.3 . ... . 1995
=> 1996! > 1995 !
=> \(\sqrt[1995]{1996}>\sqrt[1995]{1995!}\)
Ban Shadow oi, ban thieu so 1 o B roi nhe
Xin lỗi nah ,mình lỡ thiếu " + 1 " ở phần kết luận ,mong bạn tha cho !
a) So sanh: \(\sqrt{17}+\sqrt{26}+1\)va \(\sqrt{99}\)
b) CMR: \(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+...+\frac{1}{\sqrt{100}}>10\)
a)\(\sqrt{17}+\sqrt{26}+1>\sqrt{16}+\sqrt{25}+1=4+5+1=10\)
b) \(\frac{1}{\sqrt{1}}+\frac{1}{\sqrt{2}}+\frac{1}{\sqrt{3}}+.....+\frac{1}{\sqrt{100}}>\frac{1}{\sqrt{100}}+\frac{1}{\sqrt{100}}+\frac{1}{\sqrt{100}}+.......+\frac{1}{\sqrt{100}}=\frac{100}{\sqrt{100}}=10\)
so sanh 3+\(2\sqrt{2}\)va 7-\(\sqrt{3}\)
so sanh ko dung may tinh
1 )\(\sqrt{3}\) +\(\sqrt{7}\) va 2+ \(\sqrt{6}\)
2) \(\sqrt{7}\) - \(\sqrt{5}\) va \(\sqrt{6}-2\)
3) \(\sqrt{11}-\sqrt{7}vs\sqrt{7}-\sqrt{3}\)
1: \(\left(\sqrt{3}+\sqrt{7}\right)^2=10+2\sqrt{21}\)
\(\left(2+\sqrt{6}\right)^2=10+4\sqrt{6}\)
mà 2 căn 21<4 căn 6
nên căn 3+căn 7<2+căn 6
2: \(\sqrt{7}-\sqrt{5}=\dfrac{2}{\sqrt{7}+\sqrt{5}}\)
\(\sqrt{6}-2=\dfrac{2}{\sqrt{6}+2}\)
mà \(\sqrt{7}+\sqrt{5}>\sqrt{6}+2\)
nên \(\sqrt{7}-\sqrt{5}< \sqrt{6}-2\)
3: \(\sqrt{11}-\sqrt{7}=\dfrac{4}{\sqrt{11}+\sqrt{7}}\)
\(\sqrt{7}-\sqrt{3}=\dfrac{4}{\sqrt{7}+\sqrt{3}}\)
mà căn 11>căn 3
nên \(\sqrt{11}-\sqrt{7}< \sqrt{7}-\sqrt{3}\)