1、上页下页铃结束返回首页 Chapter 4 Higher-Order Differential Equation4.1 Preliminary Theory:Linear Equation上页下页铃结束返回首页上页下页铃结束返回首页11101()().()()()(1)nnnnnnd ydydyaxaxa xa x yg xdxdxdx(1)000101(),(),.,()nny xy y xyyxy4.1.1 Initial-value and Boundary-value Problems上页下页铃结束返回首页)()()()(01222xgyxadxdyxadxydxa10)(,)(yby
2、yay上页下页铃结束返回首页10)()(ybyandyay10)(,)(ybyyay10)(,)(ybyyay10)(,)(ybyyay上页下页铃结束返回首页)(),(),.,(),(011xaxaxaxann0 xx 0)(xan上页下页铃结束返回首页4.1.2 Homogeneous Equation)2(0)()(.)()(01111yxadxdyxadxydxadxydxannnnnn)3()()()(.)()(01111xgyxadxdyxadxydxadxydxannnnnn上页下页铃结束返回首页nixai,.,2,1,0),(0)(xan上页下页铃结束返回首页Dydxdy)()(
3、.)()(0111xaDxaDxaDxaLnnnn上页下页铃结束返回首页(cos4)4sin4,Dxx 222()ddyd yD DyD ydxdxdx322(56)1512Dxxxxnnnd yD ydx上页下页铃结束返回首页()(),D cf xcDf x()()()().D f xg xDf xDg x()()()(),Lf xg xL f xL g x,上页下页铃结束返回首页kyyy,.,21,.2211kkycycycy上页下页铃结束返回首页kici,.,2,1,)(11xycy)(1xy上页下页铃结束返回首页21xy xxyln22042 3yxyyx),0(xxcxcyln2221
