x2yx4+y2

(x2+y2)(x2-y2)化简(x2+y2)(x2-y2)=X^4-y^4x^4-y^4

(x2+xy+y2)-4xy(x2+y2)想疯了!乱做后得出2(x+y)(1-4xy)+xy只要2分,不必理睬

X2+Y2+Z2x²+y²+z²≤R²,表示球心在原点、半径为R的球体；x²+y²+z²≤2Rz 即 x²+y²+(z-R)

直线x2+y2x2+y2=4表示的是以（0,0）为圆心,半径是2的圆（只有那条闭合的曲线）那么这里加上一个小于,就是说,这表示（0,0）为圆心、半径是2的圆面,是一个面,而不是上面的一条线.

3y2(2y用整式分配率,分开成

x2/25+y2/16这个是线性规划的不等式椭圆内

(a2+b2)(x2+y2)你的题目是（a^2+b^2）（x^2+y^2）吧?是求展开式?展开式是a^2*x^2+b^2*x^2+*a^2*y^2+b^2*y^2(a^2+b^2)(x^2+y^2)=a^2x^2+a^2y^2+b^2x^2

(x2+y2)(x2-xy+y2)-2x2y2因式分解打开,然后再整理,就可以了~(x2+y2)(x2-xy+y2)-2x2y2=x4-x3y+2x2y2-xy3+y4-2x2y2=x4+y4-x3y-xy3=(x-y)(x3-y3)=(x

分式分解：4y2-x2/-x2-4y2+4xy4y^2-x^2/-x^2-4y^2+4xy=(x^2-4y^2)/(x^2-4xy+4y^2)=(x+2y)(x-2y)/(x-2y)^2=x+2y/x-2y4y2-x2/-x2-4y2+4x

因式分解(x2-y2)2-8(x2+y2-2)(x²-y²)²-8(x²+y²-2)=(x²+y²)²-4x²y²-8(x²+y&

(x2+2xy+y2)(x2-xy+y2)2化简(x^2+2xy+y^2)(x^2-xy+y^2)^2=(x+y)^2*(x^2-xy+y^2)^2=((x+y)(x^2-xy+y^2))^2=(x^3+y^3)^2=x^6+2x^3y^3

x2+xy+y2=19求x2+y2最小值19=x2+xy+y2x2+y2>=19×2/3=38/3

化简:(2xy-y2)-(—y2+xy)=(2xy-y2)-(—y2+xy)=2xy-y2+y2-xy=xy如果本题有什么不明白可以追问,如果满意请点击“好评”另外发并点击我的头像向我求助,请谅解,

(x2-2xy+y2)-(x2+2xy+y2)=什么-4xy-4xy(x2-2xy+y2)-(x2+2xy+y2)=x2-2xy+y2-x2-2xy-y2)=-4xy(X-y)2-(x+y)2=(x-y-x-y)(x-y+x+y)=-2y.

(x2+xy+y2)(x2+xy+2y2)-12y4=(x²+xy+y²)(x²+xy+y²+y²)-12y的4次方=(x²+xy+y²)²+y²(x

二重积分∫∫D(x2+y2)dxdy,D:x2+y2令x=p*cosa,y=p*sina那么x^2+y^2=p^2即p^20所以cosa>0那么a的范围是(-π/2,π/2)故选择答案B

(x2+xy+y2)-4xy(x2+y2)因式分解2z=2x^22xy2Y^2-2x-2y=(x^22xyy^2)(x^2-2x)(y^2-2y)2z2=(x^22xyy^2)(x^2-2x1)(y^2-2y1)=(xy)^2(x-1)^2

（x2+y2）2-（x2+y2）-6=把x2+y2看成一个整体,这样就是一个一元二次方程,就是(x2+y2-3)(x2+y2+2)若题目是此等式为0的话,则x2+y2=3(x2+y2-3)(x2+y2+2)

因式分解：(y2-4y)(y2-4y+1)-6原式=（y^2-4y）^2+(y^2-4y)-6=(y^2-4y+3)(y^2-4y-2)=(y-1)(y-3)(y^2-4y-2)

X2y2-x2-y2+1=x2(y2-1)-(y2-1)=(y2-1)(x2-1)=(y+1)(y-1)(x+1)(x-1)中的=x2(y2-1)-(y2-1)=(y2-1)(x2-1是怎么算出来的?x2(y2-1)-(y2-1),把y2-