31.03.2019 Views

Exercicios resolvidos James Stewart vol. 2 7ª ed - ingles

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

356 D CHAPTER 17 SECOND-ORDER DIFFERENTIAL EQUATIONS<br />

yp 2<br />

(x) = Bxe- zx [since y = B e- 2 x satisfies the complementary equation). Then y~ = (B- 2Bx)e- 2 "' and<br />

y~ = (4Bx- 4B)e- 2 x, and substitution gives - 5Be- 2 "' = e- 2 "' '* · B = -k· The general solution then is<br />

y(x) = c1e- 2 x + Cze 3 "' + yp 1<br />

(x) + yp 2<br />

(x) = c1e- 2 x + cze 3 x - ~- ixe- 2 "'.<br />

11. The auxiliary equation is r 2 + 6r = 0 and the general solution is y(x) = c1 + c 2 e- 6 x = k1 + k 2 e- 6

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!