Use implicit differentiation to find the points where the circle defined by
x2+y2−6x−8y=−21
has horizontal and vertical tangent lines. List your answers as points in the form (a,b).
1. Find the points where the curve has a horizontal tangent line.
Answer (separate by commas):1. Find the points where the curve has a vertial tangent line.
Answer (separate by commas):

Question

Use implicit differentiation to find the points where the circle defined by
x2+y2−6x−8y=−21
has horizontal and vertical tangent lines. List your answers as points in the form (a,b).
1. Find the points where the curve has a horizontal tangent line. 
Answer (separate by commas):1. Find the points where the curve has a vertial tangent line. 
Answer (separate by commas):

cwrw238 · Answer

2x + 2y * y' - 6 - 8y' = 0
find y'

anonymous · Answer

2x -6 = y'*(2y - 8)

anonymous · Answer

y' = (2x-6)/(2y-8)
y' = x-3/y-4

anonymous · Answer

y' = ( 2x-6 )/( 8 - 2Y )

anonymous · Answer

Horizontal line --> slope y' = ....?
Vertical line     ---> slope y' = ...?