SubArea: Trigonometric equations and inequalitiesLevel: AProject ID: 2010012001Source Problem: 1003085701Accepted: 0Clonable: 1Easy: 0Find all x, x∈R, such that tg2x=tgx.x∈⋃k∈Z{kπ;π4+kπ}x∈⋃k∈Z{kπ}x∈⋃k∈Z{π4+kπ}x∈⋃k∈Z{π2+kπ;π4+kπ}