(1)计算: ( - 2 ) 2 + tan 45 ° - ( 3 - 2 ) 0
(2)化简: x ( x + 1 ) - ( x + 1 ) ( x - 2 )
计算:(1); (2).
用计算器求下列各式的值(结果保留小数点后四位): (1)sin89°; (2)cos45.32°; (3)tan60°25′41″; (4)sin67°28′35″.
若sinα=2m-3(α为锐角),求m的取值范围.
计算:.