cho a,b la cac so duong thoa man : a+b=1
Tim gia tri nho nhat cua bieu thuc: T= \(\frac{19}{ab}+\frac{6}{a^2+b^2}+2011\left(a^4+b^4\right)\)
Cho a,b la cac so thuc duong thoa man a+b >=4 .
Tim GTNN cua P = \(\frac{2a^2+9}{a}+\frac{3b^2+2}{b}\)
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
\(P=\frac{2+a}{\sqrt{2-a}}+\frac{2+b}{\sqrt{2-b}}\)
Cho a,b duong thoa man ab=a+b.CMR:
\(\frac{1}{a^2+2a}+\frac{1}{b^2+2b}+\sqrt{\left(1+a^2\right)\left(1+b^2\right)}\ge\frac{21}{4}\)
cho a,b,c la cac so thuc duong thoa man a+b+c=3. tim gia tri nho nhat cua
P=\(\frac{a}{a^3+b^2+c}+\frac{b}{b^3+c^2+a}+\frac{c}{c^3+a^2+b}\)
cho ca so a,b,c duong thoa man ab+bc+ca =1 chung minh \(P=\frac{2a}{\sqrt{1+a^2}}+\frac{b}{\sqrt{1+b^2}}+\frac{c}{\sqrt{1+c^2}}\le\frac{1}{4}\)
cho 3 so thuc a,b,c thoa man \(\frac{1}{a+2}+\frac{3}{b+4}\le\frac{c+1}{c+3}\)
tim min cua \(q=\left(a+1\right)\left(b+1\right)\left(c+1\right)\)
cho cac so duong a;b thoa man \(\frac{a}{1+a}+\frac{2b}{1+b}=1;cmr:ab^2\le\frac{1}{8}\)
Cho phuong trinh x^2 - bx + c=0 co hi nghiem thuc duong thoa man \(X_1+x_2\ge1\)
A) c/m \(B^2-2c\ge\frac{1}{2}\)
B) Tim GTLN cua bier thuc P = \(2bc-b^3-3b+1\)