若x,y∈R,且x≥1x−2y+3≥0y≥x
x,y属于R*,且x+y=1,求证:(1)(x+1/x)(y+1/y)≥25/4 (2)(x+1/x)^2+(y+1/y
已知x,y∈R+,且x+y=1,求证:xy+1xy≥174
已知x,y∈R*,x+y=1,求证2/x+1/y≥3+2根号2
若全集I={(x,y)|x,y∈R},集合M={(x,y)|(y-3)/(x-2)},N{(x,y)|y=x=1},则(
设x,y∈R,则满足条件x+2y≥0,x-3y-5≤0.x^2+y^2-4x+2y-4≤0的点p(x,y)所在的平面区域
证明 已知xyz∈R^+, x^2x * y^2y* z^2z≥x^y+x* y^z+x * z^x+y
(1):设x+2y=1(x,y∈R),求x^2+y^2的最小值;若x≥0,y≥0,求x^2+y^2的最大值和最小值.
已知集合M={x/x/(x-1)^3≥0},N={y/y=3x^2+1,x∈R}则M交N等于
若x,y∈R+,且2x+8y-xy=0,则x+y的最小值为( )
已知 x,y,z都是正实数,且 x+y+z=xyz 证明 (y+x)/z+(y+z)/x+(z+x)/y≥2(1/x+1
设变量x,y满足约束条件x−y≥0x+y≤1x+2y≥1
若实数x,y满足x≥1x+y≤4x−2y+c≤0