Problem 14, simultaneous derivation of both sides, 2012 * (2) * (1-2x) 201= a1+2 * a2 * x+3 *.

Substitute x = 1, 2024 = a1+2 * a2+3 * a3+...+2012 * a2012.

Question 15, because SIN 2+COS 2 = 1, we know from the conditions of three-point * * * line, CPO*** line and PA+PB=2PO, then the original formula is converted into 2PO*PC, which in turn is the minimum when it is negative. At this time, let PC be x long, and the original formula becomes-.