OA là bán kính =>OA=\(\dfrac{AB}{2}=\dfrac{12}{2}=6cm\)

cường quốc

Cho các số a,b,c>0 và a+b+c\(\le\dfrac{3}{2}\).Tìm GTNN của biểu thức

\(Q=\sqrt{a^2+\dfrac{1}{b^2}}+\sqrt{b^2+\dfrac{1}{c^2}}+\sqrt{c^2+\dfrac{1}{a^2}}\)

Giải pt:\(\sqrt{x^2+2x+3}+\sqrt{x^2+x+2}=2x+2\)

42984

1.D

2.B

3.C

4.B

7

I think when I grow I will travel to africa.I think I can do something to improve the lives of these black people.Here, I can also survey their way of working and living and from there sympathize with the lack and backwardness of this country.My brother went to this country and told me that their people are very welcoming to Vietnamese people makes me very happy.I love africa too much