Find the slope of the tangent line to the ellipse x^2/9+y^2/25=1 at the point (x,y). Are there any points where the slope is not defined? If so, provide those x-values.

Question

anonymous · Answer

So far I have $$y'=\frac{ -25x }{ 9y }$$ I just do not know how to answer the second part of the question

e.mccormick · Answer

Well, are points of infinite slope or 0 slope defined?

amistre64 · Answer

x^2/9+y^2/25=1 

2x/9 + 2y/25 y' = 0

x/9 + y/25 y' = 0

y/25 y' = -x/9

y' = -25x/9y

good job on that part :)

amistre64 · Answer

what makes y' not definable?