与圆x2 y2=1和圆x2 y2-8x 7=0都相切的圆的圆心轨迹是
来源:学生作业帮助网 编辑:作业帮 时间:2024/05/29 16:01:33
y(1+x2y2)dx=xdy设xy=u,则y=u/x,dy=d(u/x)=(xdu-udx)/x^2方程化为u/x(1+u^2)dx=x*(xdu-udx)/x^2化简得u(1+u^2)dx=xdu
xy/x+y=1/3x+y=3xyx2y2/x2+y2=1/5(xy)²/[(x+y)²-2xy]=1/5(xy)²/[(3xy)²-2xy]=1/5(xy)&
(1)4x2m+1y的系数是4,次数是2m+2;-5x2y2的系数是-5,次数是4;-31x5y的系数是-31,次数是6;(2)由(1)可得2m+2=8,解得m=3.
第一式是六次四项式,最高次为6,式中已知的最高次是:--4x3y2这一项5次,所以--1/5x2ym这一项的次数必须是6次,既有2+m=6,m=4;第二式次数与第一是相同,则有2n+(5--m)=6,
x3次方y-2x2y2+xy3=xy(x²-2xy+y²)=xy(x-y)²=3x3²=27如果本题有什么不明白可以追问,再问:=xy(x2-2xy+y2)=x
(x+1)(x+3)(x-2)(x-4)+24=[(x+1)(x-2)][(x+3)(x-4)]+24=(x^2-x-2)(x^2-x-12)+24=(x^2-x-7+5)(x^2-x-7-5)+24
原式=x4+x3y+4x3y+x2y+4x2y2+4x2y2+xy2+4xy3+xy3+y4,=x3(x+y)+4x2y(x+y)+xy(x+y)+4xy2(x+y)+y3(x+y),=-x3-4x2
(2x4-4x3y-x2y2)-2(x4-2x3y-y3)+x2y2=2x4-4x3y-x2y2-2x4+4x3y+2y3+x2y2=2y3,因为化简的结果中不含x,所以原式的值与x值无关.
原式=(x^4-2x²y²+y^4)+6xy(x²+2xy+y²)-2xy(x+y)=(x²-y²)²+6xy(x+y)²
3x(M-5x)=3xM-15x2=6x2y2+N,则M=6x2y2÷3x=2xy2,N=-15x2.故答案是:2xy2,-15x2.再问:那个,谢谢姐姐,但可以讲解一下吗>_
∵M是单项式∴3x·M仍是单项式由题可得:3x(M-5x)=3x·M-15x²=6x²y²+N∴3x·M=6x²y²,-15x²=N∴M=2
解题思路:圆的参数方程解题过程:varSWOC={};SWOC.tip=false;try{SWOCX2.OpenFile("http://dayi.prcedu.com/include/readq.
原式=2x2y-2xy2-[-3x2y2+3x2y+3x2y2-3xy2]=2x2y-2xy2+3x2y2-3x2y-3x2y2+3xy2=2x2y-3x2y-2xy2+3xy2+3x2y2-3x2y
原式=[x3y2-x2y-x2y+x3y2]÷3x2y=(2x3y2-2x2y)÷3x2y=23xy-23;当x=3,y=-1时,原式=23×3×(-1)-23=-83.
5x2y+3x2y2+(-4xy2)=5x2y+3x2y2-4xy2.
(2X²-2y²)-3(X²y²+X²)+3(X²y²+y²)=2x²-2y²-3x²y&
因为x²+4y²+x²y²-6xy+1=0(x²-4xy+4y²)+(x²y²-2xy+1)=0(x-2y)²