I found the dy/dx. But how do you find a vertical tangent line? And how do you find a vertical tangent when x = (?)?

What gives division by 0? When ... [1]

Sub this back into the original function:





Solving this for y gives:

y=-0.97533487561 and y=1.08709662767

Sub these into [1] gives:

x=2.85383435874 and x=3.5433723367

These are the coordinates of the points of vertical tangency.