设y<sub>1</sub>,y<sub>2</sub>,y<sub>3</sub>都是微分方程y"+P(x)y′+Q(x)y=f(x)的解,且(y<sub>1</sub>-y<sub>3</sub>)/(y<sub>2</sub>-y<sub>3</sub>)≠常数,则该微分方程的通解为()

题目类型: 单选题

题目内容

设y1,y2,y3都是微分方程y"+P(x)y′+Q(x)y=f(x)的解,且(y1-y3)/(y2-y3)≠常数,则该微分方程的通解为()

题目选项

A. y=C1y1+C2y2+y3
B. y=C1y1+C2y2-(C1-C2)y3
C. y=C1y1+C2y2-(1-C1-C2)y3
D. y=C1y1+C2y2+(1-C1-C2)y3

正确答案

D

题目解析

∵y1-y3与y2-y3线性无关 ∴通解应设为C1(y1-y3)+C2(y2-y3)+y3整理后为C1y1+C2y2+(1-C1-C2)y3

题目纠错