如图,点E为菱形ABCD的BC边的中点,动点F在对角线AC上运动,连接BF、EF,设AF=x,△BEF的周长为y,那么能表示y与x的函数关系的大致图象是( )
A:
B:
C:
D:
如图,在△ABC中,∠A=30°,tanB=32,AC=23,则AB=( )
—I hear it's not easy to get a ticket for Fast & Furious 7. —Exactly. The film is the one this year.
已知tanθ=2,则sin2θ+sinθcosθ-2cos2θ等于( )