mathematica软件,已知y[x],Y=f1(x),X(x)=f2(x),如何plot Y[X]?
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*x
k=1
X[x] = x - k*y'[x]/(1 + (y'[x])^2)^0.5
Y[x] = y[x] + k/(1 + (y'[x])^2)^0.5
Plot[{y[x],Y[X],},{x,0,2}]
参数方程曲线绘制用ParametricPlot函数.y[x_] := x + 9.81/2*x*x;k = 1;X[x_] := x - k*y'[x]/(1 + (y'[x])^2)^0.5;Y[x_] := y[x] + k/(1 + (y'[x])^2)^0.5;ParametricPlot[{X[x], Y[x]}, {x, 0, 2}, AspectRatio->1...ClearAll["Global`*"] y[x_] := x*x; x[x_] := x; k = 1; X[x_] := x - k*y'[x]/(1 + (y'[x])^2)^0.5 Y[x_] := y[x] + k/(1 + (y'[x])^2)^0.5 ParametricPlot[{{X[x], Y[x]}, {y[x], x[x]}}, {x, 0, 2}] plot里面给定x的范围是0-2，但是显示的不是这个范围？Plot[{{X[x], Y[x]}, {y[x], x[x]}}, {x, 0, 2}]，结果出来3条线？请再帮忙看看，谢谢y[t_] := t*t;x[t_] := t;k = 1;X[t_] := t - k*y'[t]/(1 + (y'[t])^2)^0.5;Y[t_] := y[t] + k/(1 + (y'[t])^2)^0.5;ParametricPlot[{{X[t], Y[t]}, {x[t], y[t]}}, {t, 0, 2}]我改了下形参,以免参数x和函数x可能会冲突.另,ParametricPlot要X轴写在前面Y轴写在后面.你再试试看?