判斷下列廣義積分的斂散性∫x^3e^(-x^2)dx,[0,∞]

判斷下列廣義積分的斂散性∫x^3e^(-x^2)dx,[0,∞]


直接算.
=1/2∫(0,+∞)x^2e^(-x^2)dx^2
=1/2∫(0,+∞)te^(-t)dt
=1/2∫(0,+∞)e^(-t)dt
=1/2



設廣義積分∫(e→+無窮)f(x)dx收斂,且滿足方程f(x)=2/(除以)x^2-1/(除以)x乘以lnx的平方∫(e→+無


Unexpectedly only me can help you?Don't mind I sayEnglish.LetN =∫(e→+∞)f(x)dx,since this integral is convergent,it's a constantf(x)= 2/x²;- 1/(xln²;x)·∫(e→+∞)f(x)= 2/x²;-…



求定積分∫上標e下標1(1+lnx/x)dx
如題,最好詳細點,


∫上標e下標1(1+lnx/x)dx
=∫(1,e)(1+lnx)d(1+lnx)
=1/2(1+lnx)²;|(1,e)
=1/2(2²;-1)
=3/2



cos2X-2a根號(2+2cosx)大等於-3/2,求a
RT


3根號cos