Question

已知函数f(x)=tan(3x+π/4),求f(π/9)

Answer 1

因为f(x)=tan(3x+π/4),所以求f(π/9)=tan(3*π/9+π/4)=tan(π/3+π/4),

根据tan(a+b)=(tan(a)+tan(b))/(1-tan(a)tan(b)),又tanπ/3=√3,tanπ/4=1,

所以f(π/9)=(1+√3)/(1-√3)=-2-√3,

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