若△ABC的外接圆半径为2，则2bsinB+sinCc=______．_爱下问搜题

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问题填空题

若△ABC的外接圆半径为2，则

2b

sinB

+

sinC

c

=______．

答案

由正弦定理可得

b

sinB

=

c

sinC

=2r=4，

∴

2b

sinB

=8，

sinC

c

=

1

4

，

∴

2b

sinB

+

sinC

c

=8+

1

4

=

33

4

．

故答案为

33

4

．

选择题

Notice for the moment was__________ of nuclear talks between Iran and some western countries.[ ]

A. paid

B. taken

C. centred

D. given

名词解释

经验判断法