Linerar Programming of bi-variate function f(x, y) with ...

Than make a Plot 3D to have a first look. Click "Plot 3D" button and switch to the "Plot 3D2 chart. From this graph we get that all the function values are from 0 up to 40. So we set zmax=40 and zmin=0. Now, we can Plot 2D (2000 - 3000 points would be sufficient). Click two or three times the "Plot 2D" button. We can add also constrains plots ... ................
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