呵呵~~
∫(0→π/4) dθ ∫(0→secθtanθ) 1/r * rdr
= ∫(0→π/4) dθ ∫(0→secθtanθ) dr
= ∫(0→π/4) dθ [ r ] |(0→secθtanθ)
= ∫(0→π/4) secθtanθ dθ
= [ secθ ] |(0→π/4)
= sec(π/4) - sec(0)
= √2 - 1
secθtanθ的不定积分是secθ + C
呵呵~~
∫(0→π/4) dθ ∫(0→secθtanθ) 1/r * rdr
= ∫(0→π/4) dθ ∫(0→secθtanθ) dr
= ∫(0→π/4) dθ [ r ] |(0→secθtanθ)
= ∫(0→π/4) secθtanθ dθ
= [ secθ ] |(0→π/4)
= sec(π/4) - sec(0)
= √2 - 1
secθtanθ的不定积分是secθ + C