Partial Derivatives of 2-Variable Functions
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| Graph of a function f(x,y) with a point (a,b) in the plane. |
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| The intersection (in red) of the graph with the plane y = b. |
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| The plane and the intersection with the graph removed. |
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| Graph of the function f(x,b), which is just a different view of the image above. The slope of the blue line (which is tangent to the graph) is fx(a,b). |