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问题: 数学2  ~~

若arcsinx+arctg1/7=π/4,则x=___?
过程 谢谢~~~

解答:

arcsinx=π/4-arctan1/7 x=sin(arcsinx)=sin(π/4-arctan1/7)
=sinπ/4cos(arctan1/7)-cosπ/4sin(arctan1/7)

cos(arctan1/7)=(1/(1+tan(arctan1/7)^2)^0.5=(49/50)^0.5
sin(arctan1/7)=(1/50)^0.5

x=3/5