No. 237 (January 5, 2019) "39 Problems in Expanding and Contracting Logarithms (Part 1)"
No. 238 (January 12, 2019) "39 Problems in Expanding and Contracting Logarithms (Part 2)"
No. 239 (January 19, 2019) "39 Problems in Natural-Log Expansions (Part 1)"
No. 240 (January 26, 2019) "39 Problems in Natural-Log Expansions (Part 2)"
No. 241 (February 2, 2019) "10 Problems in Solving Right Triangles (Part 1 of 4)"
No. 242 (February 9, 2019) "8 Problems in Solving Right Triangles (Part 2 of 4) (Part 1)"
No. 243 (February 16, 2019) "8 Problems in Solving Right Triangles (Part 2 of 4) (Part 2)"
No. 244 (February 23, 2019) "15 Problems in Solving Right Triangles (Part 3 of 4) (Part 1)"
No. 245 (March 2, 2019) "15 Problems in Solving Right Triangles (Part 3 of 4) (Part 2)"
No. 246 (March 9, 2019) "15 Problems in Solving Right Triangles (Part 3 of 4) (Part 3)"
No. 247 (March 16, 2019) "15 Problems in Solving Right Triangles (Part 3 of 4) (Part 4)"
No. 248 (March 23, 2019) "15 Problems in Solving Right Triangles (Part 3 of 4) (Part 5)"
No. 249 (March 30, 2019) "15 Problems in Solving Right Triangles (Part 3 of 4) (Part 6)"
No. 250 (April 6, 2019) "15 Problems in Solving Right Triangles (Part 3 of 4) (Part 7)"
No. 251 (April 13, 2019) "15 Problems in Solving Right Triangles (Part 4 of 4)"
No. 252 (April 20, 2019) "10 Problems Concerning Reference Angles (Part 1 of 2) (Part 1)"
No. 253 (April 27, 2019) "10 Problems Concerning Reference Angles (Part 1 of 2) (Part 2)"
No. 254 (May 4, 2019) "15 Problems Concerning Reference Angles (Part 2 of 2) (Part 1)"
No. 255 (May 11, 2019) "15 Problems Concerning Reference Angles (Part 2 of 2) (Part 2)"
No. 256 (May 18, 2019) "15 Problems Concerning Reference Angles (Part 2 of 2) (Part 3)"
No. 257 (May 25, 2019) "15 Problems Concerning Reference Angles (Part 2 of 2) (Part 4)"
No. 258 (June 1, 2019) "16 Problems Concerning the Unit Circle (Part 1 of 2) (Part 1)"
No. 259 (June 8, 2019) "16 Problems Concerning the Unit Circle (Part 1 of 2) (Part 2)"
No. 260 (June 15, 2019) "16 Problems Concerning the Unit Circle (Part 1 of 2) (Part 3)"
No. 261 (June 22, 2019) "16 Problems Concerning the Unit Circle (Part 2 of 2) (Part 1)"
No. 262 (June 29, 2019) "16 Problems Concerning the Unit Circle (Part 2 of 2) (Part 2)"
No. 263 (July 6, 2019) "16 Problems Concerning the Unit Circle (Part 2 of 2) (Part 3)"
No. 264 (July 13, 2019) "28 Problems Solving Simple Trigonometric Equations (Type I) (Part 1)"
No. 265 (July 20, 2019) "28 Problems Solving Simple Trigonometric Equations (Type I) (Part 2)"
No. 266 (July 27, 2019) "28 Problems Solving Simple Trigonometric Equations (Type I) (Part 3)"
No. 267 (August 3, 2019) "28 Problems Solving Simple Trigonometric Equations (Type I) (Part 4)"
No. 268 (August 10, 2019) "28 Problems Solving Simple Trigonometric Equations (Type I) (Part 5)"
No. 269 (August 17, 2019) "30 Problems Solving Simple Trigonometric Equations (Type II) (Part 1)"
No. 270 (August 24, 2019) "30 Problems Solving Simple Trigonometric Equations (Type II) (Part 2)"
No. 271 (August 31, 2019) "28 Problems Solving Simple Trigonometric Equations (Type III) (Part 1)"
No. 272 (September 7, 2019) "28 Problems Solving Simple Trigonometric Equations (Type III) (Part 2)"
No. 276 (October 5, 2019) "12 Problems Solving Composite Trigonometric Equations (Type II) (Part 1)"
No. 282 (November 16, 2019) "39 Problems in Factoring by the Sum or Difference of Cubes (Part 1)"
No. 283 (November 23, 2019) "39 Problems in Factoring by the Sum or Difference of Cubes (Part 2)"
No. 284 (November 30, 2019) "60 Problems in Factoring by a Mixture of Methods (Part 1)"
No. 285 (December 7, 2019) "60 Problems in Factoring by a Mixture of Methods (Part 2) "
No. 286 (December 14, 2019) "60 Problems in Factoring by a Mixture of Methods (Part 3) "
No. 287 (December 21, 2019) "60 Problems in Factoring by a Mixture of Methods (Part 4)"
No. 288 (December 28, 2019) "60 Problems in Factoring by a Mixture of Methods (Part 5)"