The Chain Rule (derivative of a composite function)
d/dx f(g(x)) = f'(g(x))g'(x)
Derivative of y
dy/dx
Derivative of y^2
2y(dy/dx)
Derivative of e^5y
e^(5y)(5dy/dx)
Horizontal Tangent Line
y' = 0 (focus on numerator, y=k)
Vertical Tangent Line
y' = undefined (focus on denominator, x=h)