Question: Help with Graphing Directional Derivatives

I could use a hand with a problem our class has. we have the function xy+yz+zx=3 I would like to find a way to graph the surface, the tangent plane at the point (1,1,1) and the normal line all on the same graph. We have tried a couple different methods and have failed miserably. We are using Maple 10 Thanks in advance! Michael
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