已知x^2+y^2=1,x>0,y>0,且log(a)(1+x)=m,log(a)(1/1-x)=n,则log(a)y等于?A m+n B m-nC 1/2(m+n)D 1/2(m-n)...

已知x,y满足约束条件：x-y+1>=0,x+y-2>=0,x 已知x>0,Y>0,如何证x^2/y+y^2/x>=x+y 已知x^2+y^2-8x+12y+52=0 ,求1/2x-1/x-y(x-y/2x-x^2+y^2) 已知x^2+y^2-8x+12y+52=0 ,求1/2x-1/x-y(x-y/2x-x^2+y^2) 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}] x>0 y>0已知x+2y=1求 1/x+y/1最小值 已知(x+y)^2-2x+2y+1=0,则(x+y)^999= 已知集合A={(x,y)|2x-y+2>=0,x-2y+1 已知x+y=1,x>0,y>0,则2x+y/xy等于 已知x>0,y>0,2/x+5/y=1,求x+y最小值 已知x>y>0,xy=1,求x^2+y^2/x-y的最小值. 已知（x+y)²-2（x+y）+1=0,则x+y=? 已知|2x-3y|+|3x-y-1|=0,求x,y的值. 已知|x-2y+11+1x+y-5|=0项X-Y的值 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? 已知(2x+1)*2+y*2+2y+1=0 求{(x*2+y*2)-(x-y)*2+2y(x-y)}/(2y) 已知M={(x,y)|y=-x^2+mx-1},N={(x,y)|y=-x+3,0