TM NGHI^E.M T^O'NG QUAT CU'A PHU.O.NG TRNH VI PH^AN

134)

Tm nghi^e.m t^o'ng quat cu'a phu.o.ng trnh vi ph^an:

^y

⁰⁰

^{+ 3y}

⁰

^{+ 2y=xsinx}HD gia’i:

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

^y=C

¹

^e

^−x

⁺C

₂

e

^−2x

. Nghi^e.m ri^eng cu'a phu.o.ng trnh kh^ong thu^an nh^at du.o..c tm du.o.i da.ng:

^{y =}(A

1

x+A

2

) cosx+ (B

1

x+B

2

) sinx

va tm du.o..c

^A

¹

⁼⁻₁₀^{3 ;A}

²

^{= 17}₅₀^;B

¹

⁼ ₁₀^{1 ;B}

²

⁼ ₂₅³

.