广义积分∫ln(1-x^2)dx(0到1)

1个回答

  • ∫ln(1-x^2)dx

    =xln(1-x^2)-∫xdln(1-x^2)

    =xln(1-x^2)-∫x/(1-x^2)*(-2x)dx

    =xln(1-x^2)-2∫(-x^2)/(1-x^2)dx

    =xln(1-x^2)-2∫(1-x^2-1)/(1-x^2)dx

    =xln(1-x^2)-2∫dx+2∫1/(1-x^2)dx

    =xln(1-x^2)-2∫dx+∫[1/(1-x)+1/(1+x)]dx

    =xln(1-x^2)-2x+ln(1+x)-ln(1-x)+C

    积分限为0≤x≤1,则

    ∫ln(1-x^2)dx

    =[1*ln(1-1^2)-2*1+ln(1+1)-ln(1-1)]-[0*ln(1-0^2)-2*0+ln(1+0)-ln(1-0)]

    =[ln0-2+ln2-ln0]-[0-0+0-0]

    =ln2-2