... 'v"tE (0,1), va hang s6 ~ xuilt hi~n (4) la t6t nhilt theo nghla rang khong thJ thay the' no bang m9t s6 nho hall * Chung minh (4) Cho t, s E [0,1], ta co Ig(t) - g(s)1 = Igi (c)(t - s)l::; It - ... {JiLtilLinIJ tJui'e rpIuin pJm, ~ Trang 44 Th~t fa, dt;1'a vao dAng thuc (1.3), bfft dAng thuc Ostrowski (1) co th~ chung minh kha don gian hon so vdi [7] nhu sail f(x) b-aa b ff(t)dt x =- b-aa ... * Nghi~m Ie;ti ~ng s6 ~ xufft hi~n (1) Ia t6t nhfft h Gia sa C E IR tho a bfft dAng thuc I ( b (9) If(x)- b-aff(t)dt ~ C+ x a+b ) (b-aY l(b-a)~~~lfl(t)l, VxE[a,b], vdi mQi ham f: [a,b] »IR co...