利用计算器计算：利用计算器计算：( (1) )tan 2115_(_(精确到精确到0. .0001) )( (2) )tan8927 _( _(精确到精确到0. .0001) ) ( (3) )若若tan = =1. .2868，则，则 _( _(精确到精确到0. .1) )( (4) )若若tan = =108. .5729，则，则 _( _(精确精确到到0. .1) )0. .3889104. .170952. .189. .5