cho a,b,c la cac so nguyen. Chung minh rang: (a^2+b^2+c^2)*(a+b+c)^2+(ab+bc+ca)^2
1. Cho a,b,c,d la cac so nguyen thoa man \(a^2=b^2+c^2+d^2\)
chung minh rang a.b.c.d + 2015 viet duoc duoi dang hieu cua 2 so chinh phuong.
2. Cho a,b la cac so duong thoa man dieu kien a+b=1. tim gia tri nho nhat cua bieu thuc
\(P=\frac{2+a}{\sqrt{2-a}}+\frac{2+b}{\sqrt{2-b}}\)
1. Cho a,b la 2 so duong thoa a+b<=1.chung minh rang \(6b+\frac{1}{3a}+\frac{4}{b}\ge11\).
2. cho a,b,c la cac so nguyen duong sao cho (a-b).(a-c).(b-c)=a+b+c
a. chung minh rang a+b+c chia het cho 2
b. Tim gia tri nho nhat cua M=a+b+c
cho a,b,c la ba so thuc duong thoa man dieu kien a+b+c=1
chung minh rang P=\(\sqrt{\frac{ab}{c+ab}}+\sqrt{\frac{bc}{a+bc}}+\sqrt{\frac{ca}{b+ca}}\le\frac{3}{2}\)
Cho a,b,c la so duong thoa man a2+b2+c2=3. Chung minh rang
8(2-a)(2-b)(2-c)>=(a+bc)(b+ac)(c+ab)\(\ge\)
cho a, b, c la cac so duong thoa man a\(a^2+b^2+c^2=3\) . Chung minh rang : \(\frac{1}{2-a}+\frac{1}{2-b}+\frac{1}{2-c}>=3\)
cho cac so a,b,c duong thoa man ab+bc+ca=1 chung minh : \(p=\frac{2a}{\sqrt{1+a^2}}+\frac{b}{\sqrt{1+b^2}}+\frac{c}{\sqrt{1+c^2}}\)
Voi a,b,c la cac so duong thoa man a*b =c*d =1 chung minh (a+b)(c+d) + 4>= 2(a+b+c+d)
voi a,b,c,d, la cac so duong thoa man a*b = c*d =1 chung minh bat dang thuc : ( a+b )*( c+d ) +4 >= 2*( a+b+c+d ) cac ban oi giup minh voi OK