07/11/21 19:39:01
>>373
log|(1+tan(x/2))/(1-tan(x/2))|
=log|(cos(x/2)+sin(x/2))/(cos(x/2)-sin(x/2))|
分子分母にcos(x/2)+sin(x/2)をかけると倍角の公式から、
=log|(cos(x/2)+sin(x/2))^2/(cos^2(x/2)-sin^2(x/2))|
=log|(1+sin(x))/cos(x)|
07/11/21 19:39:01
>>373
log|(1+tan(x/2))/(1-tan(x/2))|
=log|(cos(x/2)+sin(x/2))/(cos(x/2)-sin(x/2))|
分子分母にcos(x/2)+sin(x/2)をかけると倍角の公式から、
=log|(cos(x/2)+sin(x/2))^2/(cos^2(x/2)-sin^2(x/2))|
=log|(1+sin(x))/cos(x)|