Let pn=1+2-3. 1. Find out the floating-point form of p2 using five-digit rounding. 2. It turns out that there exists N N+, such that the 64-bit binary machine representation of equal to the exact value of pn for n = 1, 2, ... , N, but not for N + 1. Find out this N. 3. What is the numerical value of the 64-bit representation of pn when n> N? Explain your answer. Pn is