Week 8 Theme

I opened 8.1. I checked problem 2. It wasn’t it. I tried in the middle, it wasn’t it. I then tried 8.3. 8.4, and 8.7. I checked them throughout and could not find the problem.

“It will be difficult to do trigonometric substitution on the calculus test if I can’t find how to do it,” I thought.

***

“Hey Felicia, what are you going to do your speech on?”

“I was thinking of making a modular origami cube.”

“Just a cube?”

“Well, maybe I will have more time.”

“You will have six minutes.”

“Maybe I will.”

“Could you help me on this?”

“Sure.”

“Trigonometric substitution.”

“Oh, you take this, and here is the list. If it is in the form of ‘a’ squared minus ‘x’ squared, then you use sine…”

***

“Oh, practice test,” another student said looking down at what was at a student’s vacated table.

“The recitation teacher handed them out on Friday,” I explained. “I hope you are prepared for the test without the practice test.”

“Well, I didn’t get to do 8.7, because I thought it was due on Saturday but it was really due on Friday. I got to look it over in the book once, but once.”

“It helps to do the problems to, to get them in your head,” I remarked.

“Definitely.”

“I don’t know if I will be prepared with a practice test or not,” I said. “It doesn’t seem too bad, it only has 16 problems.”

“Then the test will probably have five or six.”

“It has evaluate the improper integral-“

“That’s what was in 8.7,” he said.

“Well then, it would seem you’re in trouble,” I said. “It basically is that when one of the limits is infinity, you take the limit of the integral as ‘a’ approaches infinity, then change the limit from infinity to ‘a’…”

***

I knew that this was the problem where something was supposed to cancel. Otherwise, with e to the x power in it, the integration by parts would just keep on forever. I looked up. It was the center fielder from my baseball team walking by the classroom.

“Hey Tomas, Tomas!” he called as he passed by with his friend. I heard them talking as they went down the hallway, “That kid is sixteen, and taking Calculus II.”

“Really?”

I was glad the teacher was not in the classroom at that moment. He would not have appreciated the disturbance.

***

I set my test upside down on top of the others on the teacher’s desk. It had gone well, I thought, though I would not know for certain until Wednesday. I walked out the door, preparing my mind for baseball practice.