The y-coordinate of point A is -
. Therefore, the value of the y-coordinate of point A is -0.5.
Given that the circle is centered at the origin (0, 0) and passes through the points (1, 0) and (-1, 0) on the x-axis, it is clear that the radius of the circle is 1.
Now, point A forms a 30-degree angle from the positive x-axis and is located in the third quadrant (negative y-axis). Since the radius is 1, the coordinates of point A can be represented as (-cos(30°), -sin(30°)).
Using the trigonometric values for a 30-degree angle:
So, the coordinates of point A are
The y-coordinate of point A is -
. Therefore, the value of the y-coordinate of point A is -0.5.