dx/(x+2)(2x+1)

1/(x+x^2)dx ∫[dx/(e^x(1+e^2x)]dx ∫1+2x/x(1+x)*dx∫1+2x/x(1+x) * dx ∫(x-1)^2dx, ∫x^1/2dx x^2dx/(1-x^2)^2 ∫dx/x^2(1-x^2) ∫dx/x^2(1+x^2) ∫X^2/1-x^2 dx. dx/x^2(根号1+x^2) ∫X^2/1-x^2 dx. dx/(x+2)(2x+1) 微分方程.(1+x)^2/ (1-x)dx . ∫1/x^2+x+1dx ∫1/(x^2+x+1)dx ∫ (x+arctanx)/(1+x^2) dx 不定积分dx/x(根号1-x^2) ∫（x^2+1/x^4)dx