Monday, April 19, 2010

The End is Near

  1. An A-student in calculus came by my office and gave me some insight into why my students do so poorly on the final exam. We have an hour exam on Wednesday, and Stu came by to ask me some questions. There was a tangent line problem on the review sheet. Stu had absolutely no idea how to find a tangent line. The problem gave the point (both the x and y coordinates) and expected the students to find the slope of the tangent line and then to use the point and the slope to find the equation of the tangent line. After I reminded Stu that the derivative is the function that takes xs as inputs and outputs slopes of tangent lines, Stu still couldn't solve the problem.

  2. Stu also asked me about a derivatives question. Stu took the derivative of natural log of x and got x. Stu's reasoning is that "The natural log of x is 1/x, so the derivative is x." I reminded Stu that the derivative of the natural log of x is 1/x. Stu asked, "So what is the natural log?" Me: "Itself." This error is so common. It's the reason that students in real calculus get in trouble by assuming that the natural log has magical reciprocal powers.

  3. Requests are coming in from students who want to take the exam on a different day. From students who want to take the final exam on a different day. From students who want to know more about my absence policy.

  4. The only snarky answer that I gave to a request: We have this unwieldy web form where we are supposed to enter our students current grades for freshmen and athletes, together with a canned suggestion for improvement. (Choices are like "request meeting with instructor" or "request tutorial assistance." No choices like "Do the homework.") Today we got a request to update the system for the athletes. I have an athlete whose grade has slipped from a C- to a D+. Athlete has never been to see me even though I check the "request meeting with instructor" box every time I fill out this time-wasting form. This time in the free-form response box I ranted, "Does anyone even read these? I've told Stu to meet with me every time I've filled this out, and Stu hasn't come to meet with me. Stu's grades in math class keep falling, at it is too late in the semester to do much about salvaging them."