>>633 (上)
 1-(1/1332),
(a,b,c) = (37,9,4) のとき.

>>633 (中)
 f(a) = 1 - (1+a)/√2,       (a≦0)
    = -1 - (1+a)/√2 +2√(1+a^2), (0≦a≦1)
    = -1 + (1+a)/√2,       (a≧1)