GIA'I PHU.O.NG TRNH

22)

Gia'i phu.o.ng trnh:

^(x−ycosyx)dx+xcosyxdy= 0HD gia’i:

D - a.t

^y_x ^{=z ⇒y}

⁰

^=z

⁰

^x+z

phu.o.ng trnh du.o..c du.a v^e da.ng:

Zxcosz.z

⁰

+ 1 = 0⇔coszdz =−dxx +C ⇔sinz=−ln|x|+C

V^a.y TPTQ:

^sin_x^{y =−ln|x|+C}