求不定积分ln(1+p^2)pdp

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/12 05:36:32
求不定积分ln(1+p^2)pdp

求不定积分ln(1+p^2)pdp
求不定积分ln(1+p^2)pdp

求不定积分ln(1+p^2)pdp
原式=1/2∫ln(1+p^2)dp^2
=1/2∫ln(1+p^2)d(1+p^2)
=1/2*(1+p^2)*ln(1+p^2)-1/2∫(1+p^2)dln(1+p^2)
=1/2*(1+p^2)*ln(1+p^2)-1/2∫(1+p^2)*1/ln(1+p^2)d(1+p^2)
=1/2*(1+p^2)*ln(1+p^2)-1/2∫d(1+p^2)
=1/2*(1+p^2)*ln(1+p^2)-1/2(1+p^2)+C
=1/2*(1+p^2)*[ln(1+p^2)-1]+C

典型的分部积分!先用m 换P^2 再用 t换1+m
原式 = 0.5* 积分 ln(t)dt 后面就用分布积分
=0.5*tlnt -0.5t
再换回来 t=1+p^2
=0.5(1+p^2)ln(1+p^2)-0.5(1+p^2)