12 Chapter 2. Second-Order Linear Equations. Section 2.4. THE USE OF A KNOWN SOLUTION TO FIND ANOTHER. Page 74

12.1 problem 1(a)
12.2 problem 1(b)
12.3 problem 2
12.4 problem 3
12.5 problem 4
12.6 problem 5
12.7 problem 6(a)
12.8 problem 6(b)
12.9 problem 6(c)
12.10 problem 7
12.11 problem 8