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):

anonymous · Answer

$$x^{2} + y ^{2} - 6 x - 8y + 21 =0$$

anonymous · Answer

abscissa points???

anonymous · Answer

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