8. Let \( (x, y) \) be a point on the unit circle. In each of the following situations, determine the requested value exactly.
a. Suppose that \( x=-0.3 \) and \( y \) is negative. Find the value of \( y \).
b. Suppose that \( (x, y) \) lies in Quadrant II and \( x=-2 y \). Find the values of \( x \) and \( y \).
c. Suppose that \( (x, y) \) lies a distance of \( \frac{29 \pi}{6} \) units clockwise around the circle from \( (1,0) \). Find the values of \( x \) and \( y \).
d. At what exact point(s) does the line \( y=\frac{1}{2} x+\frac{1}{2} \) intersect the unit circle?