- CHAPTER 9. -
Section 9.1 2a+b Setting x oe 0 /<> results in the algebraic equations OE &< $
For a nonzero solution, we must have ./>aA < Ib oe <# ' < ) oe ! . The roots of the characteristic equation are <" oe # and <# oe % . For < oe #, th
- CHAPTER 8. -
Section 8.1 2. The Euler formula for this problem is C8" oe C8 2^& >8 $C8 , C8" oe C8 &82# $2 C8 ,
in which >8 oe >! 82 Since >! oe ! , we can also write
a+b. Euler method with 2 oe !& >8 C8 8oe# !" "&*)! 8oe% !# "#*#) 8oe' !$
- CHAPTER 6. -
Section 6.1 3.
The function 0 a>b is continuous. 4.
The function 0 a>b has a jump discontinuity at > oe " . 7. Integration is a linear operation. It follows that (
-9=2 ,> /=> .> oe
" E ,> => " E ,> => ( / / .> ( / / .> # !
- CHAPTER 5. -
Section 5.1 1. Apply the ratio test : lim aB $b8" k a B $b 8 k
Hence the series converges absolutely for kB $k " . The radius of convergence is 3 oe " . The series diverges for B oe # and B oe % , since the n-th term does not a
- CHAPTER 4. -
Section 4.1 1. The differential equation is in standard form. Its coefficients, as well as the function 1a>b oe > , are continuous everywhere. Hence solutions are valid on the entire real line. 3. Writing the equation in standa
- CHAPTER 3. -
Section 3.1 1. Let C oe /<> , so that C w oe < /<> and C ww oe < /<> . Direct substitution into the differential equation yields a<# #< $b/<> oe ! . Canceling the exponential, the characteristic equation is <# #< $ oe ! The ro
- CHAPTER 2. -
Section 2.1 1a+b
a,b Based on the direction field, all solutions seem to converge to a specific increasing function. a- b The integrating factor is .a>b oe /$> , and hence Ca>b oe >$ "* /#> - /$> It follows that all solutions co
- CHAPTER 1. -
Section 1.1 1.
For C "& , the slopes are negative, and hence the solutions decrease. For C "& , the slopes are positive, and hence the solutions increase. The equilibrium solution appears to be Ca>b oe "& , to which all other so