问题
填空题
若sin(π+α)=
|
答案
∵sin（π+α）=-sinα=3 5
∴sinα=-3 5
=cos(-α)+sin(-α-
)+1π 2 sin(3π-α)-cos(-α-
)π 2
=cosα-cosα+1 sinα+sinα
=-1 2sinα 5 6
故答案为：-
．5 6
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若sin(π+α)=
|
∵sin（π+α）=-sinα=3 5
∴sinα=-3 5
=cos(-α)+sin(-α-
)+1π 2 sin(3π-α)-cos(-α-
)π 2
=cosα-cosα+1 sinα+sinα
=-1 2sinα 5 6
故答案为：-
．5 6