第五章 常微分方程
二阶可降阶类型
<span class="equation-text" contenteditable="false" data-index="0" data-equation="y^ (n) =f(x)类型" style=""><span></span><span></span></span>
<span class="equation-text" contenteditable="false" data-index="0" data-equation="y''=f(x,y')类型" style=""><span></span><span></span></span>
<span class="equation-text" contenteditable="false" data-index="0" data-equation="y''=f(y,y')类型" style=""><span></span><span></span></span>