x^2 y^2 xy=a^2的图形面积-搜答案-拍题作业网

由X+Y=3XY可得X+Y-XY=2XY,用X+Y-XY替换分母中的2XY,所以(2X+2Y-XY)/(X+Y+2XY)=(2X+2Y-XY)/(2X+2Y-XY)=1

x-xy=8(1)xy-y=-9(2)则有(1)-(2):X-XY-XY+Y=X+Y-2XY=8-(-9)=17

x^2+xy+y=14y^2+xy+x=28两式相加x^2+y^2+2xy+x+y=42(x+y)^2+(x+y)-42=0(x+y-6)(x+y+7)=0x+y=6或x+y=-7

X-a的绝对值+（y+4）的平方=0绝对值和平方都是非负值,只有他们同时为0时,和才为0所以x-a=0,y+4=0=>x=a,y=-4A-2B=2x^2-4xy+6y^2+3x-y-2x^2+4xy-

x=-10:0.1:10;y=x;>> [X,Y]=meshgrid(x,y);>> Z=2*X.^2-2*X.*Y+Y.^2-3*X+Y;>>

x^2-3xy+4y^2=(x^2+xy)+4(y^2-xy)=a+4

因为x-y=4xy所以x-2xy-y=2xy2x+3xy-2y=11xyx-2xy-y分之2x+3xy-2y=5.5

x+y=3xy,所以2x+2y-xy/x+y+2xy=(2×3xy-xy)/(3xy+2xy)=5/5=1

xy=-a2+a+2=(2-a)(a+1)=[-(2-a)][-(a+1)]则x=2-ay=a+1x+y=3或者x=-(2-a)y=-(a+1)x+y=-3又因为x+y=3所以x=2-ay=a+1

(x-2y)(x+y)+(x+y)=0(x+y)(x-2y+1)=0因此是表示直线x+y=0或x-2y+1=0

你这是贝努力双纽线,极坐标方程是ρ²=a²sin2θ求面积时求一个叶的乘以2就可以了.面积=2∫[0,π/2](1/2)ρ²dθ=∫[0,π/2]a²sin2θ

用双十字做xy常13113-4（x+3y+1)(x+3y-4)=0y=-(x+1)/3y=(4-x)/3图像自己画再问：。。。

a-2b=(5x²y-3xy²+4xy)-2(7xy²-2xy+x²y)=5x²y-3xy²+4xy-14xy²+4xy-2x&#

1、x-y=a+32x+y=5a二式相加得3x=6a+3,得x=2a+1代入得y=a-2所以方程组解为x=2a+1,y=a-22、2a+1＞a-2,解得a＞-3a-2＞0,解得a＞2综上可得a＞23、

6x^2-5xy+y^2-8x+2y-8=(3x-y+2)*(2x-y-4)=0,故有3x-y+2＝0或2x-y-4＝0,接着就会做了吧.答案是64/3.（该三角形在X轴的边为8/3,由Y=3X+2=

3/5再问：详细过程呢再答：y-x=3xyx-y=-3xy代入得：(-6xy+3xy)/(-3xy-2xy)=-3/-5=3/5

分解因式(将x看成常数,解出y)得(x+y)(x-2y)=0所以是两条直线y=-x和y=1/2x,还要除去y=0(即x轴)

∵x-y/xy=3∴x-y=3xy2x+3xy-2y/x-2xy-y=[2(x-y)+3xy]/[(x-y)-2xy]=(6xy+3xy)/(3xy-2xy)=9xy/(xy)=9

x+y=5xy（2x-3xy+2y)/(x+2xy+y）=[2（x+y）-3xy]/[(x+y)+2xy]=(2×5xy-3xy)/(5xy+2xy)=7xy/7xy=1再问：若x＋1/x＝3,求(x

7派平方a立方,!刚才在一个题目里面回答过了,再发一次答案好像不对吧?我觉得应该小于6pi平方a立方.