x,y∈R.x+y=1 求证(x+2²+(y+2)²≥25/2
x,y∈R.x+y=1 求证(x+2²+(y+2)²≥25/2
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*,x+y=1,求证2/x+1/y≥3+2根号2
若x,t∈{x∈R|x>0},切x+y>2,求证:(1+x)/y
集合A={y|y=x²-1,x∈R},B={y|y=-2x²+2,x∈R},求A∩B
集合A{y|y=x²-1,x∈R},B{y|y=-2x²+2,x∈R}求A∩B
设P={y[y=-x²+1,x∈R}.Q={y[y=2^x,x∈R},则( )
已知集合A={(x,y)|(y-2)/(x-1)=a+2,x,y∈R},B={(x,y)|(a²-4)x+(a
已知x,y属于正R,且x+2y=1,求证xy=
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(
已知x+2y=1,x,y∈R,求x^2y的最大值
x,y∈R+,1/x+1/y=4,则x+2y最小值?