Answer:
Step-by-step explanation: 58 - 3 = 55.
x² + y² = 9 is the equation of a circle with center (0, 0) and radius 3.
This puts the vertices at (-3, 0), (3, 0), (0, -3), and (0, 3).
When is the tangent line vertical? <em>when it passes through the x-axis.</em>
Answer: (-3, 0), (3, 0)