2(1) 微分方程即 dy/dx = 2xy/(3x^2-y^2) 是齐次方程。令 y = xu, 则 u+xdu/dx = 2u/(3-u^2) ,xdu/dx = (u^3-u)/(3-u^2)(3-u^2)du/(u^3-u) = dx/x[1/(u+1)+1/(u-1)-3/u]du = dx/xln[(u^2-1)/u^3] = lnx + lnC(u^2-1)/u^3 = Cx通解 y^2-x^2 = Cy^3