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**John's question at Yahoo! Answers regarding implicit differentiation & horizontal/vertical tangents**

Here is the question:

I have posted a link there to this topic so the OP can see my work.Implicit Differentiation Problem?

For the equation x^2+xy+y^2=y;

(a) Find the points where the tangent line is parallel to the x-axis. (b) Find the points where the tangent line is parallel to the y-axis.