已知sinα cosβ=√3/2 cosα sinβ=√2 求tanαcotβ的值網友廻答：
- 以a,b代替α,β
sina cosb=根號3/2
平方得:
sin^2a 2sinacosb cos^2b=3/4.(1)
cosa sinb=根號2
平方得:
cos^2a 2sinbcosa sin^2b=2.(2)
(1) (2):
1 2(sinacosb sinbcosa) 1=11/4
即2sin(a b)=3/4
sin(a b)=3/8
tana*cotb
=sina/cosa*cosb/sinb
=(sinacosb)/(cosasinb)
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