*This preview shows
pages
1–2. Sign up to
view the full content.*

This ** preview**
has intentionally

**sections.**

*blurred***to view the full version.**

*Sign up*
**Unformatted text preview: **(3 x 2 y 2 + 4 e y + 2) + (2 x 3 y + 4 xe y-9 y 2 ) y = 0 is exact and nd the solution. Sometimes a dierential equation is not exact but becomes exact when you multiply by some function ( x,y ). Then ( x,y ) is called an integrating factor . There are various tricks that sometimes work to produce integrating factors, e.g., Problems 23 and 24 on page 100, but we will be satised with knowing what integrating factors are and what they are good for. EXAMPLE. Show that the given equation is not exact but becomes exact when multiplied by the given integrating factor. Then solve the equation. " 3 x + 6 y # dx + " x 2 y + 3 y x # dy = 0 , ( x,y ) = xy HOMEWORK: SECTION 2.6...

View Full
Document