微积分不定积分 10
1个回答
展开全部
∫(x+2)/√(4x^2+4x+5) dx
=(1/8)∫(8x+4)/√(4x^2+4x+5) dx -2∫dx/√(4x^2+4x+5)
=(1/4)√(4x^2+4x+5) - ln|√(4x^2+4x+5) +(2x+1)| + C
------
4x^2+4x+5 = (2x+1)^2 +4
let
2x+1 = 2tanu
dx = (secu)^2 . du
∫dx/√(4x^2+4x+5)
=∫(secu)^2 . du/(2secu)
=(1/2)∫secu du
=(1/2)ln|secu+tanu| + C'
=(1/2)ln|√(4x^2+4x+5)/2 +(2x+1)/2| + C'
=(1/2)ln|√(4x^2+4x+5) +(2x+1)| + C''
=(1/8)∫(8x+4)/√(4x^2+4x+5) dx -2∫dx/√(4x^2+4x+5)
=(1/4)√(4x^2+4x+5) - ln|√(4x^2+4x+5) +(2x+1)| + C
------
4x^2+4x+5 = (2x+1)^2 +4
let
2x+1 = 2tanu
dx = (secu)^2 . du
∫dx/√(4x^2+4x+5)
=∫(secu)^2 . du/(2secu)
=(1/2)∫secu du
=(1/2)ln|secu+tanu| + C'
=(1/2)ln|√(4x^2+4x+5)/2 +(2x+1)/2| + C'
=(1/2)ln|√(4x^2+4x+5) +(2x+1)| + C''
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询