cos15°•sin75°-sin15°•cos75°的值是（）A．12B．32C．-12D．-32

Question

cos15°•sin75°-sin15°•cos75°的值是（　　）

A．(1)/(2)
B．(√(3))/(2)
C．-(1)/(2)
D．-(√(3))/(2)

(1)/(2)
B．(√(3))/(2)
C．-(1)/(2)
D．-(√(3))/(2)(1)/(2)1122
(√(3))/(2)
C．-(1)/(2)
D．-(√(3))/(2)(√(3))/(2)√(3)√(3)√(3)

3

322
(1)/(2)
D．-(√(3))/(2)(1)/(2)1122
(√(3))/(2)(√(3))/(2)√(3)√(3)√(3)

3

322

Answer 1

cos15°•sin75°-sin15°•cos75°=sin（75°-15°）=sin60°=(√(3))/(2)
故选B (√(3))/(2)√(3)√(3)√(3)

3

33222
故选B