已知x.y∈R,且y=x^2,求证:log2(2^x+2^y)>7/8
已知x.y为实数,且y=x平方,求证log2(2的x次方+2的y次方)>7/8
已知x,y属于正R,且x+2y=1,求证xy=
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f(x)的定义域为R,对任意x,y∈R,有f(x+y)+f(x-y)=2f(x)f(y),且f(0)≠0.求证:y=
已知x,y∈R,且2x+8y-xy=0,求x+y的最小值
已知x,y∈R*,x+y=1,求证2/x+1/y≥3+2根号2
已知函数f(x)满足f(x+y)+f(x-y)=2f(x)f(y)(x∈R,y∈R),且f(0)≠1.
已知x,y,z∈R+,且x+y+z=3,求证:x^2/(y^2+z^2+yz)+y^2/(x^2+z^2+zx)+z^2
若x,y∈R+,且2x+8y-xy=0,则x+y的最小值为( )
已知x,y∈R,且(x-2)^2+y^2=3,那么y/x的最大值是?
已知x,y属于R+,且2x+8y-xy=0,求x+y的最小值.
已知x,y∈R+,且x+y=1,求证:xy+1xy≥174