3(x-1)的三次方y-(1-x)的立方z-搜答案-搜搜考试网

1、(x+y)乘(x-y)的三次方+(x+y)的三次方乘(y-x)=（x+y)(x-y)((x-y)²-(x+y)²)=（x+y)(x-y)(x-y+x+y)(x-y-x-y)=-

令2x平方加3x三次方加1为t,则y=cos三次方t令cost为a,则y=a的三次方.所以导数为3cos平方（2x平方加3x三次方加1）*{-sin（2x平方加3x三次方加1）}*（4x+9x的平方）

已知x=4/5,y=-1/5,求x三次方-y的三次方+3x平方y-3xy的平方x三次方-y的三次方+3x平方y-3xy的平方=(x-y)³=[4/5-(-1/5)]³=(4/5+1

x³y+2x²y²+xy³=xy(x²+2xy+y²)=xy(x+y)²=1×3²=9

6.联立a-b=30,b-c=25,两式相加,得a-c=55,a方-b方=1650可拆分成（a+c)(a-c)=1650,除以前面得出来的就是a+c=305.既然无意义,说明y-5为0,就是y为5,x

(x+y)²=1x²+y²+2xy=1xy=-1(x+y)^3=x^3+y^3+3x^2y+3xy^2=x^3+y^3+3xy(x+y)x^3+y^3=(x+y)^3-3

已知x+y=1,则x^3+y^3+3xy=（x+y）(x^2-xy+y^2)+3xy=1×(x^2-xy+y^2)+3xy=x^2-xy+y^2+3xy=x^2+2xy+y^2=(x+y)^2=1^2

x+y=1则x^2+y^2+2xy=1因为x^2+y^2=3则xy=-1x^3+y^3=(x+y)(x^2-xy+y^2)=1*(3+1)=4

X+Y=1X³+Y³+3XY=(X+Y)(X²-XY+Y²)+3XY=X²-XY+Y²+3XY=X²+2XY+Y²=(X

-3（1/2x³-1/3y³+1/6）+2（1/3x³-1/2y³+1/4）=-3/2x³+y³-1/2+2/3x³-y³

因为绝对值和二次平方都不可能是负数,所以从第一句可以得知得数为0.所以：x-3=0y+1=0x=3y=-1即x3=27y3=-1

首先x3-y3=(x-y)(x2+xy+y2)其次x3-y3-3xy=1所以x3-y3=1+3xy=(x-y)(x2+xy+y2)x-y=(1+3xy)/(x2+xy+y2)=(1+3xy)/[(x-

x+y=1,平方,x^2+2xy+y^2=1,又x^2+y^2=3,所以xy=-2x^3+y^3=(x+y)(x^2-xy+y^2)=1*(3+2)=5

绝对值平方大于等于0所以此题只有0+0=0满足题意|x+2|=0；(y+1)²=0解得x=-2;y=-1-3(x-2y)³-2(2x-y)³=-3(0)³-2(

原式=(x+y)³×[2(x+y)]³×[3(x+y)]³=(1/2)³×1³×(3/2)³=1/8×27/8=27/64

A=x³＋2x²y＋2y³－1,B=3＋y³－2x²y＋2x³∵A+B+C=0∴C=－A－B=－x³－2x²y－2y&#

x三次方-3x²y+3xy²+4x²y-xy²+y的三次方=x三次方+2xy²+x²y+y的三次方当x=-1,y=-3时原式=-1-18-3

x^3-3x和y^3-3y都可以看成g(x)=x^3-3x对g(x)分析一下x=-1时极大值2x=1时极小值-2所以f(x,y)x=y=1时取极小值-3x=y=-1时取极大值5