已知tanα=2,求sin2α的值

来源:学生作业帮助网 编辑:作业帮 时间:2024/08/01 18:21:42
已知tanα=2,求sin2α的值
x){}KKm|gγMřyF6>aMR>A5v6ę3mD4g hM@I 4 kkLMm s VL1_4d };|

已知tanα=2,求sin2α的值
已知tanα=2,求sin2α的值

已知tanα=2,求sin2α的值
sin2α
=2sinacosa
=2sinacosa/(sin^2 a+cos^2 a)
=2tana/(tan^2 a+1)
=2*2/(2^2+1)
=4/5

sin2α=2tana/(1+tan^2a)=4/5

sin2α
=2sinacosa
=2sinacosa/(sin^2 a+cos^2 a)
=2tana/(tan^2 a+1)
=2*2/(2^2+1)
=4/5

sin2a=2*sina*cosa tana=sina/cosa