1. Alternately a fair coin is tossed and a fair die is thrown, beginning with the coin, What is the probability that the coin wil register with a 'head' before the die register a '5' or '6'?
2. Lef f be a funciton with domain [-1,1] such that the coordinates of each point (x,y) of its graph satisfy x^2+y^2 = 1. The total number of points at which f is neccisarily conitinous is ?
A. 0 B. 1 C. 2 D 4. E infinity
No2: If f=sqrt(1-x^2),for x=Q(rational number);-sqrt(1-x^2),for otherwise x=R-Q(irrational number),only x=1 or -1,f is continous(Strictly speaking,they are only semicontinous).