来自解小华的问题
tanα=sin2α/(1+cos2α)=(1-cos2α)/sin2α怎么得出tanα=(1+sin2α-cos2α)/(1+sin2α+cos2α)?
tanα=sin2α/(1+cos2α)=(1-cos2α)/sin2α怎么得出tanα=(1+sin2α-cos2α)/(1+sin2α+cos2α)?
1回答
2020-08-21 16:47
tanα=sin2α/(1+cos2α)=(1-cos2α)/sin2α怎么得出tanα=(1+sin2α-cos2α)/(1+sin2α+cos2α)?
tanα=sin2α/(1+cos2α)=(1-cos2α)/sin2α怎么得出tanα=(1+sin2α-cos2α)/(1+sin2α+cos2α)?
sin2α=(1+cos2α)*tanα1-cos2α=sin2α*tanα两式相加:sin2α+1-cos2α=(1+cos2α+sin2α)*tanα(把公因式tanα提出)所以tanα=(1+sin2α-cos2α)/(1+sin2α+cos2α)其实这算是一个定理:k=a/...