<正>We give a systematic account of results which assure positivity and bounded- ness of partial sums of cosine or sine series.New proofs of recent results are
For 1/4 < a <√2/4, let S1(x) = ax, S2(x) = 1 - a + ax, x ∈ [0,1]. Ca is the attractor of the iterated function system {S1, S2}, then the packing measure of Ca &