tan(z)=tan(x+yi)=sin(x+iy)/cos(x+iy)
sinxcoshy+icosxsinhy
=----------------------
sinxcoshy-icosxsinhy
cosxsinx+icoshysinhy
=----------------------------------
cos^2(x)cosh^2(y)+sin^2(x)sinh^2(y)
sin2x+isinh2y
=-----------------------------
cos2x+cosh2y
分子部分我知道是兩倍角
所以分母會變成2(cos^2(x)cosh^2(y)+sin^2(x)sinh^2(y))
可是我不懂為什麼可以換成 cos2x+cosh2y
請板上高手解答一下QQ
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※ 編輯: kuut 來自: 140.115.204.42 (11/08 10:53)
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