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判断甲组命题中,分别属于乙的哪一类型。(甲)命题(1)直线 a 在平面α内的射影为直线 b,若 c⊥b,则 c⊥a.(2)若 a+b≥2(ab)~(1/2),则 a∈R~+,b∈R~+.
Judgment of which of the two types belonged to Group A propositions. (a) Proposition (1) The projection of line a in plane α is line b. If c⊥b, then c⊥a. (2) If a+b≥2(ab)~(1/2), then a ∈R~+, b∈R~+.