61.6 Chapter 1, section 1.2. Riccati Equation. subsection 1.2.4-2. Equations with hyperbolic tangent and cotangent.

61.6.1 problem 18
61.6.2 problem 19
61.6.3 problem 20
61.6.4 problem 21
61.6.5 problem 22
61.6.6 problem 23
61.6.7 problem 24
61.6.8 problem 25
61.6.9 problem 26
61.6.10 problem 27