x^2+xy+y^2=1 求x^2-xy+y^2的取值范围 答案为1/3到3
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/26 22:57:11
x^2+xy+y^2=1 求x^2-xy+y^2的取值范围 答案为1/3到3
x^2+xy+y^2=1 求x^2-xy+y^2的取值范围 答案为1/3到3
x^2+xy+y^2=1 求x^2-xy+y^2的取值范围 答案为1/3到3
设x^2-xy+y^2=p
∵x^2+xy+y^2=1
∴可知x^2+y^2=(1+p)/2
2xy=(1-p)
∵x^2+y^2≥2|xy|
∴(1+p)/2≥│(1-p)│
∴1/3≤p≤3
∴x^2-xy+y^2∈[1/3,3]
1-2/x+y=xy,4y+6x=xy.求xy的解?
若1/x-1/y=2,求3x-2xy-3y/x-xy-y的值3x-2xy-3y/x-xy-y 不好意思,是3x-2xy-3y/x-2xy-y
xy^2-e^x+e^y=1 求y' 是xy^2 不是xy
已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)
已知xy-x-y=11,求(xy-1)^2+(x+y-2)(x+y-2xy)的值.
x+y=1,xy=-2求(x²+y²+xy)/(x²+y²-xy)
已知1/x-1/y=2,求3x+7xy-3y/2x-3xy-2y答案是1/x-1/y=2(y-x)/xy=2 得:x-y=-2xy(3x+7xy-3y)/(2x-3xy-2y)=[3(x-y)+7xy]/[2(x-y)-3xy]=(-6xy+7xy)/(-4xy-3xy)=xy/(-7xy)=-1/7 谁能帮我解释一下=[3(x-y)+7xy]/[2(x-y)-3xy]=(-6xy+7xy)/(-4xy-3xy) 是怎
若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
x-y=1,xy=2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知x y=1,xy=-3,求2xy-4x 4(y-2(xy-x))
y/x=ln(xy) 求dy/dx(xy-y^2)/(xy+x^2)
已知x-xy=8,xy-y=-9,求x+y-2xy的值
当x-y=2xy时,求4x-3xy-4y/xy
3X^2+XY+Y=15 求XY.
当x=3,y=3分之1时,求代数出3xy-[2xy-2(xy-2分之3xy)+xy]+3xy的值
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
若xy满足x²+2x+y-2√y-1=-1,求xy,