一阶线性微分方程。
y'+(1-2x)/x^2·y=1
应用通解公式,应该不难啊!
通解为
y=x^2【C·e^(1/x)+1】
此题最简单解法:积分因子法。
解:∵y²dx+(y²+2xy-x)dy=0
==>e^(1/y)*y²dx+e^(1/y)*(y²+2xy-x)dy=0
(方程两端同乘e^(1/y))
==>e^(1/y)*y²dx+e^(1/y)*(2y-1)xdy+e^(1/y)*y²dy=0
==>e^(1/y)*y²dx+xd[e^(1/y)*y²]+e^(1/y)*y²dy=0
==>d[xy²e^(1/y)]+e^(1/y)*y²dy=0
==>xy²e^(1/y)+∫e^(1/y)*y²dy=C
(C是积分常数)
∴原方程的通解是xy²e^(1/y)+∫e^(1/y)*y²dy=C。
怎么做的啊?我不会