The polar coordinates go by the pattern (r, θ) where r = radius and θ = the angle.
In the first polar coordinate, the radius is 3 and the angle is pi/2 or 90°.
Therefore, to plot this, the point should be 3 units away from the center at a 90° angle from the x-axis. See the graph below. The first point is shown by the black dot.
Moving on to the second polar coordinate, the angle is -5π/6. Since the angle is negative, we will measure the angle in a clockwise rotation.
In addition, since the radius is a negative number, the point will be 3 units away from the center and opposite the location of the angle.
See the second point below.
Lastly, for the third coordinate, the radius is 4, therefore, the point is located 4 units from the center.
The angle is 5pi/4 or 225°. See the third point below.
Let's combine the three points in one graph.