GIA'I PHU.O.NG TRNH

102)

Gia'i phu.o.ng trnh:

^{2y” + 5y}

⁰

^{= 29xsinx}HD gia’i:

Phu.o.ng trnh da.c tru.ng:

^2λ

²

^{+ 5λ= 0 ⇔λ}

¹

^{= 0, λ}

²

⁼⁻⁵₂5x

Nghi^e.m t^o'ng quat cu'a phu.o.ng trnh thu^an nh^at

^y=C

¹

^+C

²

^e

⁻

2

V

^±i

kh^ong pha'i la nghi^e.m cu'a phu.o.ng trnh da.c tru.ng n^en tm nghi^e.m ri^eng da.ng:

y= (Ax+B) sinx+ (Cx+D) cosx

Thay vao phu.o.ng trnh du.o..c:

^{A =−2; B = 185}₂₉^{; C =−5; D=−16}₂₉