# Calculus help: Finding derivative of (xy + x^3y) and relative extreema

**Question description**

I need help finding dy/dx of xy + x^3y first. To do this, do you use the product rule and the chain rule so for xy it would be (x*y' + y*1)*y' and then for x^3y it would be (x^3*y' + y*3x^2) y'? Then I also need to write the equation for the tangent line at each of the points where the x coordinate is 1, and what of these tangent lines are vertical. The original curve given is xy^2 - x^3y = 6. In addition to this, are the points where x = 1 relitive extreema? if not, how do you find relative extrema?

I am sorry about the abundance of information there. I was home sick and really just want to get all this done, but am afraid I do not yet understand it very well. Thank you for all your help! I am not sure how to make this more clear, and I really do not know how this site works, or what the best way is for me to get help on this site. Thank you again for all your help!

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