The loose minute hand of a clock is spun hard. The coordinates (x,y) of the point where the tip of the hand comes to rest is noted. Z is defined as the sgn function of the product of x and y, where sgn(t) is 1 if t>0, 0 if t=0 and -1 if t<0
a) Find and plot the cdf of the random variable X.
b) Does the cdf change if the clock hand has a propensity to stop at 3,6,9 and 12 o'clock?