计算: | - 2 | - 2 cos 60 ∘ + 1 6 - 1 - ( π - 3 ) 0 .
计算 (1) (2)(a+1)2﹣a(a﹣1)
计算:
(11·十堰)计算:-2-1+︱-1︱.
(11·丹东)(本题8分)计算: