21/04/03 08:35:22.11 6/URXYd7d
df/dx=f を満たす関数
f(x)=lim(n→∞)=(1+x/n)^n=exp(x)
exp(x+y)=exp(x)exp(y)
zが純虚数iyのとき
exp(iy)=cos(y)+i*sin(y)
dg/dx=1/x を満たす関数
g(x)=lim(ε→0)(x^ε-1)/n=log(x)
log(xy)=log(x)+log(y)
zが絶対値1の複素数でz=c+siのとき
log(z)
=arccos(c) (s>=0)
=arcsin(s) (c>=0)