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已知x的2次方加y的2次方加xy减3y加3等于0,求x的y...

x2+y2+xy-3y+3=0 (x2+xy+1/4*y2)+(3/4*y2-3y+3)=0 (x+y)^2+3(1/2y-1)^2=0 x+y=0 1/2y-1=0 y=2 x=-2 x^y=4

x^2+y^2+xy-3y+3=0 (x + (1/2)y )^2 + (3/4)y^2 - 3y +3 =0 (x + (1/2)y )^2 + (3/4)( y^2 - 4y +4) =0 (x + (1/2)y )^2 + (3/4)( y -2)^2 =0 x+(1/2)y = 0 and y=2 x= -1 and y=2 x^y =(-1)^2 =1

x^2+y^2=(x+y)^2-2xy = 9-4=5 (x-y)^2 = (x+y)^2-4xy =9-8 =1 x-y = 1 or -1

x^2-xy=-32xy-y^2=-82x^2+4xy-3y^2=2x^2-2xy+6xy-3y^2=2(x^2-xy)+3(2xy-y^2)=2×(-3)+3×(-8)=-30

由已知等式,令x=sin³θ,y=cos³θ x²+y² =(sin³θ)²+(cos³θ)² =(sin²θ)³+(cos²θ)³ =(sin²θ+cos²θ)(sin⁴θ-sin²θcos²θ+cos⁴θ) =(sin²θ+cos²...

1764804605 x二次方加y二次方的值

已知x加y等于4,xy等于2,求x的平方减xy加y的平方的值

X^2+3xy-4y^2=(x+4y)(x-y)=0 x+4y=0或x-y=0; x=-4y或x=y 将x值代入算式x-y/x+y : 1、(-4y-y)/(-4y+y)=5/3 2、(y-y)/(y+y)=0.(y不等于0) 答案为5/3或0.

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