1．sin 95°＋cos 175°的值为( ) a．sin 5° b．cos 5° c．0 d．2sin 5° 解析：选c.原式＝cos 5°－cos 5°＝0. 2．下列与sin(θ－π2)的值相等的式子为( ) a．sin(π2＋θ) b．cos(π2＋θ) c．cos(32π－θ) d．sin(32π＋θ) 解析：选d.sin(θ－π2)＝－cos θ，经验证知只有sin(32π＋θ)＝－cos θ. 3．若sin(π＋α)＋cos(π2＋α)＝－m，则cos(3π2－α)＋2sin(6π－α)＝( ) a．－m2 b.m2
