2x + a x≤0 (4). Let_ f(x)= is continuous in(-[infinity], +[infinity]), then a= \e*(sinx+cosx) x>0 (4) 2 (B) 0 (C) 1 (D) 3 x²-x (5). The number of the infinite discontinuous points of the function f(x) = - x²-1 (4) 2 (B) 0 (C) 1 (D) 3 (6) .If f(x) is derivative at ƒ(a+x)−ƒ(a−x) _ x=a, then lim x→0 X (A) f'(a). (B) 2ƒ'(a). (C) 0. (D) f'(2a). is