求y=x的平方-2x-3的定义域
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/05 15:08:12
3x^2+xy-2y^2=(3x-2y)(x+y)=0x=-2y/3,或x=-y但由于你要求的式子中分母里有X平方-Y平方x=-y舍去其他就代入吧
4x^2-3y^2=73x^2+2y^2=19相加7x^2-y^2=26所以14x^2-2y^2=2(7x^2-y^2)=2*26=52
:|x+二分之一|+(y-3)的平方=0∴x+1/2=0y-3=0∴x=-1/2y=3(3x+2y)的平方-2(x-y)(x+y)+3(x+y)(x-2y)=9x²+12xy+4y²
解所求代数式=4x^2-12x+9-x^2+y^2-y^2=3x^2-12x+9=3(x^2-4x-1)+3+9把x^2-4x-1=0代人3(x^2-4x-1)+3+9=12所以所求代数式的值是12
∵x²+y²+2=3∴x²+y²=3-2=1∴-3x²-3y²=-3
x²-4x+y²-10y+29=0x²-4x+4+y²-10y+25=0(x-2)²+(y-5)²=0∵(x-2)²≥0,(y-5
y=x的平方-4x+3=(x-2)^2-1所以:y≥-1y=-3x的平方+5x-2=-3(x^2-5x/3+25/36)+25/12-2=-3(x-5/6)^2+1/2所以:y≤1/2
3x的平方-6y+2=3×(x的平方-2)+2=3×5+2=17
(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)/(2y)=X^2-y^2-y^2+X^2+y^2-2xy-3x^2+xy=-x^2-y^2-xy=-(x^2+y^2+xy-3
x²-x-x²+y=-3-x+y=-3x-y=3x²+y²-2xy=(x-y)²=3²=9
上题整理得:(X-Y)-(X-Y)平方+2=0得(X-Y)平方-(X-Y)-2=0(X-Y-2)(X-Y+1)=0得到X-Y=2或者-1
x^2+y^2-2x-4y+5=0(x^2-2x+1)+(y^2-4y+4)=0(x-1)^2+(y-2)^2=0∴(x-1)^2=0(y-2)^2=0∴x-1=0x=1∴y-2=0y=2所以x=1,
先由两已知方程解得x=27/8,y=9/8,然后接下来的自己算啦...两方程的话,先将第二个两边都乘三,再于第一个相减得出y,再将y带进方程得x
x的平方+y的平方-2x+4y=-5x²-2x+1+y²+4y+4=0﹙x-1﹚²+﹙y+2﹚²=0x-1=0,y+2=0x=1,y=-2
x(x-1)-(x²-y)=-3x²-x-x²+y=-3y-x=-3x-y=3x²+y²-2xy=(x-y)²=3²=9
X=2,Y=1.2的平方+1=5或X=1,Y=2.1的平方+2=3
由x-2y=0得x=2y,x²=4y²,当x,y都不为0时,(2x²-3y²)/(x²+5y²)=(8y²-3y²)/(
X=3+Y,将其带入X+Y=7也就是3+Y+Y=7,Y=5带入X-Y=3也就是X-5=3,X=8所以X的平方+Y的平方=X乘以X+Y乘以Y=8乘以8+5乘以5=64+25=89x的平方+y的平方=89
x^2-6x+8y+y^2+25=0x^2-6x+9+y^2+8y+16=0(x-3)^2+(y+4)^2=0(x-3)^2=0,(y+4)^2=0x=3,y=-42x-3y=2*3-3*(-4)=6