(1)求sin795°的值；
(2)已知cosφ=
),求sin(φ-
). 
(1)求sin795°的值；
(2)已知cosφ=
),求sin(φ-). 解析:(1)原式=sin(720°+75°)=sin75°
=sin(45°+30°)
=sin45°cos30°+cos45°sin30°
=
+)=
.(2)∵cosφ=
),∴sinφ=
∴sin(φ-
-cosφsin
=
×
-
×
=
.