TM NGHI^E.M RI^ENG CU'A PHU.O.NG TRNH

53)

Tm nghi^e.m ri^eng cu'a phu.o.ng trnh:

^y

⁰

^{+ siny+xcosy+x= 0}

thoa' ma~n di^eu ki^e.n d^au

^{y(0) = π}₂

.

HD gia’i:y

⁰

+ siny+xcosy+x= 0 ⇐⇒ y

⁰

+ 2 siny2cosy2+x.2 cos

²

y2 = 0⇐⇒ y

⁰

+ tany2+x= 02 cos

²

y2

da.t

^{z = tany}₂ ^{=⇒ z}

⁰

^{= y}

⁰

, phu.o.ng trnh thanh phu.o.ng trnh tuy^en tnh

z

⁰

+z =−x

. Gia'i ra:

^{z = 1−x+Ce}

^−x

thoa' ma~n di^eu ki^e.n d^au

^{y(0) = π}₂

khi

^{C = 0}

. V^a.y nghi^e.m ri^eng

^y= 2 arctan(1−x)

.