9 Section 8.3. The Lagrange and Clairaut equations. Exercises page 72

9.1 problem 220
9.2 problem 221
9.3 problem 222
9.4 problem 223
9.5 problem 224
9.6 problem 225
9.7 problem 226
9.8 problem 227
9.9 problem 228
9.10 problem 229