0.3x-0.8y=0.5 0.5x-0.4y=0.8 求方程组的解并画图!

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}] 已知|3x+y-0.5|+(x+2y+1.5)^2=0,求代数式（x-y)(x-2y)-3x(1/3x-y)+(2x+y)(2x-y) 快. 已知x>=0,y>=0,求证0.5(x+y)^2+0.25(x+y)>=x√y+y√x （x+3y)²-2（x-y)（x+y)+(x+y)²其x=0.5,y=-2 (x-y)(x+xy+y)+xy(y-x) 其中x=7.1 y=2.92x+y=0,2x-y=0.5,求2x^2-1/2y^2 0.3x-0.5y=0写成含y的代数式表示x 给位懂matlab的朋友们急求z=0.8-（0.3x^2+x+y^2+y-0.05)*(0.5+y)/(0.55+y+y^2)的三维图.其中x取值范围-0.1到0.1y取值范围0到0.我每次出现这样错误[x,y]=meshgrid(-0.1:0.1,0:0.3);>> z=0.8-(x+y^2+y-0.05+0.3*x^2)*(0.5+y)/(0.55+y+ A={（x,y)|y>=0.5|x-2|},B={(x,y)|y （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 若x:y=0.5:0.8 y:z=1.2:0.5 则x:y:z matlab高手帮忙看程序!我要画matlab图,f 随x,y变化,怎么不会出现图形呢,程序如下,请大师帮忙看程序哪里出错了,clcx=0:0.2:10;y=x;f=x.^5.*y.^5.*0.1.^(y-1).*0.3.^(y-1).*0.5.^(y-1).*0.8.^(y-1).*0.9.^(y-1).*exp(-x.*(0.1.^y matlab画二元函数图像z = (x/(x+y) + 1.96*1.96/(2*(x+y)) - 1.96 * ((x/(x+y)*(1-x/(x+y))+1.96*1.96/(4*(x+y)))/(x+y))^0.5)/(1+1.96*1.96/(x+y))该怎么画 已知x+y=-4试计算多项式0.5(x+y)+4(x-y)-3(x-y)-1.5(x+y)-x+y的值 已知x：y=0.5:0.3,y:z=1/5:1/2,求x:y: y={x+[x+(x)^0.5]^0.5}^0.5求导 Matlab编程问题 cos(x*y)*cos(x*(1-y))-0.5x*sin(x*y)*sin(x*(1-y))=1;怎样才能画出x-y关系图呢x的取值范围为0,1 解方程组：（0.2x+0.1y）/2- （4x-y）/10=（x-y）/5+ (3x+0.5y)/30 (3x+2y-1)/8=3-(0.8x-5y)/41=-=