Hello i was testing out wolfram|Alpha for the first times with 2 variables functions and it seems that it’s pretty inacurate.
As u can see in the image below, where i zoomed the contour plot, a point that is in clearly in the orange part has a lower value than a point clearly in the red part. it should be the contrary since the whiter the higher right ?
What was the meaning of the comma in your input? W|A interpreted it as a separator of a 2-vector. I wonder if this is what you really meant:
Plot3D[(472.5 + x)*(101.8 + y), {x, 0, 500}, {y, 0, 20}]
ContourPlot[(472.5 + x)*(101.8 + y), {x, 0, 500}, {y, 0, 20}]
If you look closely at the “Input interpretation”, you will see that W|A has interpreted your input as the plot of the dot product of two vectors, not as the product of two linear polynomials. Try using US-style decimal numbers:
Plot3D[(472.5+x)*(101.8+y), {x, 0, 500}, {y, 0, 20}]
wow thanks a lot i didnt know a dot instead of a coma could put me in trouble like this ! as i said i’m new with this tool ! have a great day