∫(上限π/4,下限0)x/(1+cos2x) dx
=∫(上限π/4,下限0)x×/(1/2×(secx)^2) dx
=1/2×∫(上限π/4,下限0)x dtanx
=1/2×[π/4-∫(上限π/4,下限0) tanx dx] tanx的原函数是-ln|cosx|
=π/8-ln2/4
∫(上限π/4,下限0)x/(1+cos2x) dx
=∫(上限π/4,下限0)x×/(1/2×(secx)^2) dx
=1/2×∫(上限π/4,下限0)x dtanx
=1/2×[π/4-∫(上限π/4,下限0) tanx dx] tanx的原函数是-ln|cosx|
=π/8-ln2/4