coordinatetransform.wl

(* Mathematica *)
Plot[
 Piecewise[{{1 x, 1.5 > x > 0}}, {{0, x > 1.5}}],
 {x, 0, 4},
 TicksStyle -> Directive[Opacity[0]],
 PlotStyle -> Red,
 PlotRange -> {{0, 4}, {0, 5}},
 Epilog -> {
   Opacity[0.25], Gray, 
   Polygon[{{1.5, 1.5}, {2.5, 2.25}, {3, 5}, {2, 4.25}}],
    Black, Text[MaTeX["\\text{d}A"], {2.4, 2.8}],
   Opacity[1],
   Text[MaTeX["\\vec{R}"], {0.75, 0.4}],
   Arrow[{{1.5, 1.5}, {3, 5}}], 
   Text[MaTeX["\\vec{\\nabla R}"], {2.1, 3.4}],
   Blue, Arrow[{{1.5, 1.5}, {2.5, 2.25}}], 
   Arrow[{{2, 4.25}, {3, 5}}],
   Orange, Arrow[{{2.5, 2.25}, {3, 5}}], 
   Arrow[{{1.5, 1.5}, {2, 4.25}}],
   Text[MaTeX["\\frac{\\partial R}{\\partial u}\\text{d}u"], {2.1, 
     1.4}],
   Text[MaTeX["\\frac{\\partial R}{\\partial v}\\text{d}v"], {1.5, 
     3.1}]
   }
 ]