Final answer:
The polar equation r = -1 represents a circle with a radius of 1 unit, centered at the origin but in the opposite plane from the starting angle, as the equation is independent of the angle θ.
Step-by-step explanation:
The given polar equation is r = -1. To sketch this graph, note that in polar coordinates, r represents the distance from the origin to a point and can be positive or negative. Negative values of r indicate that the point is in the opposite direction from the positive polar axis at the specified angle.
However, the equation r = -1 doesn't depend on the angle θ, meaning that for every angle, the point is one unit away from the origin, but in the direction opposite to that of the increasing θ. Therefore, this equation represents a circle with a radius of 1 unit centered at the origin, but located in the plane opposite to the initial starting angle (usually the positive x-axis).