高等数学不定积分两小题?

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高等数学不定积分两小题?
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高等数学不定积分两小题?
高等数学不定积分两小题?

高等数学不定积分两小题?

不用下压缩包了东西一样的!


  1. 设 x = 2sint,则 dx = 2cost*dt

    ∫dx/[x*√(4-x^2)]

    =∫2cost*dt/[2sint*2cost]

    =∫dt/(2sint)

    =1/2*∫dt/sint

    =∫d(t/2)/{2tan(t/2)*[cos(t/2)]^2}

    =1/2*∫[sec(t/2)]^2*d(t...

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    1. 设 x = 2sint,则 dx = 2cost*dt

      ∫dx/[x*√(4-x^2)]

      =∫2cost*dt/[2sint*2cost]

      =∫dt/(2sint)

      =1/2*∫dt/sint

      =∫d(t/2)/{2tan(t/2)*[cos(t/2)]^2}

      =1/2*∫[sec(t/2)]^2*d(t/2)/tan(t/2)

      =1/2*∫d[tan(t/2)]/tan(t/2)

      =1/2ln|tan(t/2)| + C

      =1/2*ln|sin(t/2)/cos(t/2)| + C

      =1/2*ln|2sin(t/2)cos(t/2)/{2[cos(t/2)]^2}| + C

      =1/2*ln|sint/(1+cost)| + C

      =1/2*ln|(x/2)/[1+√(1-x^2/4)]| + C

      =1/2*ln|x/[2+√(4-x^2)]| + C

      =1/2*ln|x| -1/2*ln|2+√(4-x^2)| + C

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