Cho x;y la hai so duong thay doi. Tim gia tri nho nhat cua bieu thuc:
S=(x+y)^2/x^2+y^2. + (x+y)^2/xy
Giai chi tiet giup mk nha!! Cam on!
gia tri nho nhat cua :
\(x+y+z=?\)
BIET \(\sqrt{x}+\sqrt{y}+\sqrt{z}=1\)
CHO GIAI TRI TIET NHA CAC BAN!
1 tim gia tri lon nhat cua (x+z)(y+t) biet x^2+y^z^2+t^2=1
2 tim gia tri lon nhat cua (x+z)(y+t) biet x^2+y^2+2z^2+2t^2=1
Tim tat ca cac so nguyen x,y thoa man x^2 + 8y^2 - 6y - 2x + 6y + 6 = 0. ai biet giai giup minh voi,toan nang cao lop 9 do,cam on moi nguoi nhieu
cho x;y;z duong thoa man xyz=1
tim gia tri nho nhat cua \(\frac{1}{x^2\left(y+z\right)}+\frac{1}{y^2\left(x+z\right)}+\frac{1}{z^2\left(x+y\right)}\)
tim gia tri nho nhat cua \(\frac{1}{1+xy}+\frac{1}{1+yz}+\frac{1}{1+xz}\)voi x;y;z>0 va x^2+y^2+z^2<=3
2. giai phuong trinh: \(\sqrt{2x+3}+\sqrt{5-2x}=3x^2-12x+14\)(neu cach giai)
3. tim gia tri nho nhat cua: \(\frac{x+8}{\sqrt{x}+1}\)
4. tim gia tri nho nhat cua: \(\frac{4a}{b+c-a}+\frac{9b}{a+c-b}+\frac{16c}{a+b-c}\)
5. cho a;b;c la 3 canh cua tam giac thoa man a+b+c=2 ; 0<a;b;c<1 c/m a^2+b^2+c^2+2abc<2
6. giai he phuong trinh 6(x+y)=5xy ; 12(y+z)=7zy ; 4(z+x)=3xz
7. cho a; b;c la 3 canh cua 1 tam giac c/m voi moi x,y,z \(\frac{x^2}{a^2}+\frac{y^2}{b^2}+\frac{z^2}{c^2}>\frac{2\left(x^2+y^2+z^2\right)}{a^2+b^2+c^2}\)
8. cho x;y;z>0 thoa man x+y+z=2008 c/m \(\frac{x^4+y^4}{x^3+y^3}+\frac{y^4+z^4}{y^3+z^3}+\frac{z^4+x^4}{z^3+x^3}>hoac=2008\)
cho x;y;z>0 thỏa mãn x^2+y^2+z^2<=3
tim gia tri nho nhat cua \(\frac{1}{1+xy}+\frac{1}{1+yz}+\frac{1}{1+xz}\)
giai giup minh voi
cho 0 <= X<= 3/2.tim gia tri lon nhat cua y=x(3-2x)2