The symmetry axis of (1) is -B/2A, that is, 1/2-a, and the function has no zero point, then f (1/2-a) >; 0, just put it into the equation and get a square.

(2) 1/2-a=2, then a=-3/2, and f(x)=x squared+(2a-1) x+1= f (x) = x squared-4x+/kloc-0. 0, (x-2) square >; 5, so x & gt2+ radical number 5 or x < 2- radical number 5.