x=0,1,2时y=1,0.5,0.2.求分段线性插值函数

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}] 设x大于1,y大于0,x^y+x^-y=2根号二,x^y-x^-y等于? 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. 0.2X^2Y-0.5XY^2-0.3X^2Y+0.7X^2Y,当x=-1,y=2/3时,最后=? (x+y)+(2x+0.5y)+(3x+1/6y)+...+(9x+1/72y),当x=2,y=9时,求代数式的值 (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 已知x,y满足约束条件：x-y+1>=0,x+y-2>=0,x 当x=-1 y=-2时求代数式[2x^2-(x+y)(x-y)][(-x-y)(-x+y)+2y^2]的值 当x=2 y=2分之1 时,代数式(x+y)(x-y)+(x-y)^-(x^-3xy ) 若|x+y-1|+（x-y-2)²=0,求代数式（x+2y)(x-2y）-（2x-y)(-y-2x)的值. 当x+y/x-y=1/2时,求代数式x-y/x+y-2x+2y/x-y的值 当x-y/x+y= -1/2时,求y-x/x+y -2x+2y/x-y的值.（要有过程) {4x-3y-10=0 3x-2y=0,{3x-4(x-y)=2 2x-3y=1,{2(x+y)-(x-y)=3 (x+y)-2(x-y)=1 已知2x-y=0,求分式【1+（3*y*y*y/x*x*x-y*y*y）】/【1+（2y/x-y）】的值注：x*x*x-y*y*y=（x-y）*（x*x+xy+y*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) （x-y)(x+y)-(x+y)^2+2y(y-x),其中x=1,y=3. 解方程组：①4x+3y-5=0,x-2y-4=0.②5x-2=2（y-1）,2（x-2）+（y-1）③0.2x+0.5y=0.2,0.4x+0.1y=0.4④3x-13y=-12,x+3y=2