求不定積分∫(e^2x)/(2+e^x)dx 如題

求不定積分∫(e^2x)/(2+e^x)dx 如題


答:
∫[(e^x)^2/(2+e^x)] dx
=∫[e^x /(2+e^x)] d(e^x)
=∫[(e^x+2-2)/(2+e^x)] d(e^x)
=∫[1-2 /(e^x+2)] d(e^x+2)
=e^x-2ln(e^x+2)+C



求不定積分∫(x^2+x)* e^(2x)


∫(x^2+x)* e^(2x)dx
=1/2∫(x^2+x)*de^(2x)
=1/2(x^2+x)*e^(2x)-1/2∫e^(2x)*(2x+1)dx
=1/2(x^2+x)*e^(2x)-1/4∫(2x+1)de^(2x)
=1/2(x^2+x)*e^(2x)-1/4(2x+1)*e^(2x)+1/4∫2e^(2x)dx
=1/2(x^2+x)*e^(2x)-1/4(2x+1)*e^(2x)+1/4e^(2x)+C
= 1/2x^2e^(2x)+C



如題,求e^(2x)/(e^x+1)^3不定積分,


∫e^2x dx/(e^x+1)^3
=∫e^(-x)dx/(e^(-x)+1)^3
=-(1/2)(1/(e^(-x)+1)^2)+C



不定積分求解:∫(2x^2+2x+20)/[(x^2+2x+5)(x-1)]dx


∫{(2x^2+2x+20)/[(x^2+2x+5)(x-1)] }dx= 2∫{(x^2+2x+5)/[(x^2+2x+5)(x-1)] }dx -∫(2x-10)/[(x^2+2x+5)(x-1)] dx= 2∫[1/(x-1)]dx -∫(2x-10)/[(x^2+2x+5)(x-1)] dxlet(2x-10)/[(x^2+2x+5)(x-1)≡A/(x-1…