x>0,y>0,2/x+1/y=1,若x+2y>m的平方+2m恒成立,则实数M的取值范围

若x+y=1,x不等于0则x+(2xy+y^2)/x/(x+y)/x= 若|x+y-1|+（x-y-2)²=0,求代数式（x+2y)(x-2y）-（2x-y)(-y-2x)的值. 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 设x大于1,y大于0,x^y+x^-y=2根号二,x^y-x^-y等于? mathematica软件,已知y[x],Y=f1(x),X(x)=f2(x),如何plot Y[X]?y[x_] := x + 9.81/2*x*xk=1X[x] = x - k*y'[x]/(1 + (y'[x])^2)^0.5Y[x] = y[x] + k/(1 + (y'[x])^2)^0.5Plot[{y[x],Y[X],},{x,0,2}] 若x,y满足|2x-y-3|+|3x+2y+1|=0,则x= y= 若x,y满足|x-y+1|+(x+y+3)^2=0则x^2-y^2= 若|x+y+1|+(x-2y)的平方=0,则x+2y=? 若(x+y)(x+y-1)-2=0,求x+y的值求 若(2x-y-1)2+|x-2y-3|=0,求代数式(2x+y)(2x-y)-(x+2y)(x-2y-1)的值若(2x-y-1)²+|x-2y-3|=0,求代数式(2x+y)(2x-y)-(x+2y)(x-2y-1)的值 若y=x(x-1)(x-2)(x-3),则y′（0）= 若实数x,y满足x-y+1》=0,x+y>=0,x 若实数x,y满足x-y+1>=0,x+y>=0,x 已知x,y满足约束条件：x-y+1>=0,x+y-2>=0,x 已知x属于R,y>0,集合A={x|x*x+x+1,-x,-x-1},集合B={-y,-y/2,y+1}若A=B,则x*x+y*y的值为 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 y=1/x^2(x>0) y=(1-x)/(1+x) y=(e^x-e^-x)/2 y=1-x^2 x>=0 ,y=sin|x|/x x