I am trying to plot this function with Plot3D and ContourPlot and they both give blank boxes. Is there something wrong with my code?
f[x_, y_] = 4*Sin[x - 2] + 4*Cos[y - 4] + 9*x^2 - 5*xy + 1*y^2 - 2*x + 4*y
I suggest you use the delayed evaluation ":=". For example,If we set x=1;the define a function x+2 with direct assignment and delayed assignment,respectively.The following answer we will get.
Hi Katelyn,
You did not post the code you tried so it is not possible to identify what is wrong with it.
f[x_, y_] := 4 Sin[x - 2] + 4 Cos[y - 4] + 9 x^2 - 5 x y + 1 y^2 - 2 x + 4*y Plot3D[Evaluate@f[x, y], {x, -2 Pi, 2 Pi}, {y, -2 Pi, 2 Pi}]
Try
f[x_, y_] := 4Sin[x - 2] + 4Cos[y - 4] + 9x^2 - 5x*y + 1y^2 - 2x + 4*y ; Plot3D[f[x,y],{x,-Pi,Pi},{y,-Pi,Pi}]
