cho a>0,b>0 chung minh căn(a+b)/2>(căna+cănb)/2
ai giai dc xin cam on
cho a,b,c>0 thỏa căna^2+b^2 + cănb^2+c^2 + cănc^2+a^2=3căn2
CMR: a^2/(b+c) + b^2/(c+a) + c^2/(a+b) >=3/2
Tìm a,b thuộc Z sao cho:
a, căna + cănb = căn2
b, 3căn a + 9cănb = căn7
Cho a,b>0 , a+b=1. Chung minh rang:
\(\frac{2}{ab}+\frac{3}{a^2+b^2}\)≥14.
Moi nguoi giai giup minh voi, mai kiem tra roi. Cam on truoc nha!
\(P=3\left(\frac{1}{a^2+b^2}+\frac{1}{2ab}\right)+\frac{1}{2ab}\ge\frac{3.4}{a^2+b^2+2ab}+\frac{2}{\left(a+b\right)^2}=\frac{14}{\left(a+b\right)^2}=14\)
Dấu "=" xảy ra khi \(a=b=\frac{1}{2}\)
Cho s b,c>0
Chứng minh rằng a/a+b+b/b+c+c/c+a< căn a/b+c+cănb/c+a+cănc/a+b
Cho a/b <1 va a,b thuoc N, b khong bang 0, c > 0. Chung minh a/b < a+c/b+c
Giup minh nhe! Cam on
cac ban giai giup minh bai tap nay khan cap nhe:
cho cac so a,b,c la ba so nguyen khac 0, thoa man: ab/(a+b)=bc/(b+c)=ac/(a+c) ( gia thiet cac ti le thuc deu co nghia). tinh M= (ab + bc + ca)/(a^2+b^2+c^2)
xin cam on rat nhieu
Cho hai duong thang xOx' va yOy' cat nhau tai Otren duong thang xOx' lay ba diem A,B,C sao choOA=OB=BCTren duong thang yoy' lay ba diem M,N,P sao cho OM=ON=NP. chung minh MA,NC,PB cung di qua 1 diem.
GIAI GIUP MINh nhe mn☺☺☺☺☺xin cam on
Rút gọn:
a/ \(\frac{a\sqrt{b}+b\sqrt{a}}{\sqrt{ab}}:\frac{1}{\sqrt{a}-\sqrt{b}}\) (a,b>0,a#b)
b/(1+ a+căna/căna +1).(1- a.căna/căna -1) (a>=0,a#1)
a)\(\frac{a\sqrt{b}+b\sqrt{a}}{\sqrt{ab}}:\frac{1}{\sqrt{a}-\sqrt{b}}\)
b) \(\left(\frac{1+a+\sqrt{a}}{\sqrt{a}+1}\right).\left(\frac{1-a-\sqrt{a}}{\sqrt{a}-1}\right)\)
thế này à
chung minh rang neu a,b,c la cac so khac 0 thoa man ab+ac/2=bc+ba/3=ca+cb/4 thi a/3=b/5=c/15
mk dg can gap nha
ai lm dc (giai ki) mk tick cho