计算:
计算: (1) (2)
计算: (1)-3-(-4)+7; (2)(+-)×(-36); (3)-14―(―5)×+(-2)3
计算 (1)2sin30°-cos45° (2)sin230°+cos230° (3)2sinα-="0" (4)tanα-1=0
计算 (1) (2)
(1) (2) (3) (4)化简求值:(其中)