# [✓] ContourPlot 2 variables functions in W|A?

GROUPS:
 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 ?link to the wolfram page to see it in live
 Gianluca Gorni 1 Vote 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}] 
 Michael Rogers 1 Vote 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}]