圆方程X^2 Y^2-4X=1,圆心坐标是多少?圆半径是多少?

曲线y=4(x+1)²/(x²+2x+4)=4(x+1)²/[(x+1)²+3]=4-12/[(x+1)²+3]可得,当x趋于±∞时,12/[(x+1

2x+y=4x-y-1/22x-2y-1/2=08x-8y-4=01式4x-y-1/2=10+6x+2y/42x+6y/4+21/2=08x+6y+42=02式2式-1式得到：8x+6y+42-8x+

水平渐近线,即是当x趋于无穷时y的极限值（如果存在的话）这里y=4(x^2+2x+1)/(x^2+2x+4)当x->∞时,y=4所以水平渐近线为y=4再问：这个极限怎么求的再答：lim(x->∞)4(

x²+y²-4x+1=0x²-4x+4+y²=3(x-2)²+y²=3令x=2+√3cosa,y=√3sinax+y=2+√3cosa+√3

x^2+y^2-4x-2y+1=0(x-2)^2+(y-1)^2=4x^2+y^2=4x+2y-1设(x-2)^2=k(y-1)^2=4-kx^2+y^2+x+y=5x+3y-1x=2+根号ky=1+

圆C1；x*x+y*y+4x+y+1=0.1圆C2：X*X+Y*Y+2X+2Y+1=0.21式减2式,得2x-y=0,即y=2x.33式代入1式,得5x^2+6x+1=0,得x=-1或x=-1/5,则

(3x+2y)/4=（2x+y）/55*(3x+2y)=4*(2x+y)15x+10y=8x+4y7x=-6yx=-6/7y(2x+y)/5=(x-y+1)/66*(2x+y)=5*(x-y+1)12

2(1-x)=2x2-2x=2x2=2x+2x4x=2x=1/24分之3y-1=74分之3y=8y=8除以4分之3y=3分之324分之(y+2)-6分之2-3=04分之(y+2)=6分之2+34分之(

4x+2y=oy=-2x代入x²+4x²=1x²=1/5x=±√5/5y=-2x所以x=√5/5,y=-2√5/5或x=-√5/5,y=2√5/5

令m=x(x+y),n=y(x+y)则m-n=x^2-y^2,于是m-n+1=2x^2,1-m+n=2y^2(m+n-1)^2=4x^2y^2=(m-n+1)(1-m+n)整理得：m^2+n^2-m-

1.4(x-y-1)=3(1-y)+3.5①(x/2)+(y/3)=2②整理原方程组,由①得：4x-y=10.5③,由②得：3x+2y=12④由③得,y=4x-10.5⑤,将它带入④得,3x+2(4x

解1：(x+y)-(x+y)^2=(x+y)(1-x-y)解2：2x²=3x2x²-3x=0x(2x-3)=0x1=0,x2=3/2解3：(3x-1)²-4=0(3x-1

(x-1)²+(y-1)²=1令x-1=cosa则x=1+cosa(y-1)²=1-cos²a=sin²a所以y-1=sinay=1+sinax&su

解1）设y/x=k,那么y=kx,换句话说只要求出k的最大值和最小值即可关于实数方程我们可以改成圆方程即（x-2)^2+y^2=3不难看出直线y=kx与圆相切的时候k值有最大值和最小值.即（x-2)^

y^4+2x^4+1=4x^2yy^4-2y^2+1+2(x^4-2x^2y+y^2)=0(y^2-1)+(x^2-y)=0y^2=1,x^2=yy1=1,y2=-1,(当y=-1时,x^2-y不能等

2y^2-4y+1=0还得附加条件y不等于0?

设x-y=b,是一直线方程,显然,当直线与圆相切时b可以取得最大值和最小值.x^2+(x-b)^2-4x+1=0当判别式等于0即可求出b的最值.

(x+y)/2+(x-y)/2=7====>x=74(x+y)-5(x-y)=2====>-x+9y=2将x=7代入-x+9y=2====>y=1所以x=7,y=1.

(3x+2y）/4=x+1/3y得x=2/3y(3x+2y）/4=3(x-2）+y得9x+2y-24=0故y=3,x=2