Took my first diff. eq. exam this morning

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In summary, the professor allowed for students to come to class early to start the exam. However, if a student does not know how to use variation of parameters, the question can be quite tedious and lengthy.
  • #1
Shackleford
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I took linear algebra last fall, and it's my first math class since then. As such, I was a bit worried going into it.

Eight problems. I went through the first six rather straightforwardly. However, two of the last three consumed much more time. I kind of started to freak out as I was aware time was getting short. I didn't even get to start the last problem because I ran out of time. If I had more time, I could have worked it correctly. We had about an hour and twenty minutes.

I know that should be more than enough time; I'm just upset I didn't get to finish. I mentioned this to the professor in an email, but I doubt it'll be taken into any consideration.

How do you professors out there look at a situation like this?
 
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  • #2
It happened to me several times (I'm a student). Ultimately I wrote in the exam : "I have too few time in order to do the other exercises". As an answer I got "Next time manage better your time".
 
  • #3
I'm not surprised.

I just wish an extra 15 minutes could be given if you have like one problem left or whatever.
 
  • #4
the most they can do is add extra time during the exam. You can't blame them, well unless the exam way really time consuming. Even case of a really time consuming exam, most likely majority did not get through it either...which means there is a higher curve.

if you claim you skipped a qn b/c you did not have time...how are they to know you are not just making an excuse? One could just present "not enough time" as an excuse for not solving a problem that they did not have a clue of.
 
  • #5
rubrix said:
the most they can do is add extra time during the exam. You can't blame them, well unless the exam way really time consuming. Even case of a really time consuming exam, most likely majority did not get through it either...which means there is a higher curve.

if you claim you skipped a qn b/c you did not have time...how are they to know you are not just making an excuse? One could just present "not enough time" as an excuse for not solving a problem that they did not have a clue of.

Well, I can understand that. Whenever time was up, there was still quite a bit of people working on it. I'd say half, probably a little more, actually. I can hope for a small curve, but if not, I'll be happy with a B.
 
  • #6
yeah tests are annoying, especially when time is the hardest part about it. At least it will prepare you for when you are doing research as a mathematician and you will have someone standing behind you with a watch telling you that you have 50 minutes left.
 
  • #7
Do you think your instructor would allow you to come to class early to start the exam? When I took differential equations my instructor designed the exams so the students could actually finish in the time allotted. So long as we knew the methods, the questions were fairly straight forward. For example, solving a problem using variation of parameters could easily be a page of tedious calculations or relatively simple depending on the homogeneous solution. Whether the solution is long and tedious or simple, the student requires knowledge of how to employ variation of parameters. The rest is mostly algebra.

Although even with this, only on rare occasion did somebody finish during class.
 
  • #8
irises28 said:
yeah tests are annoying, especially when time is the hardest part about it. At least it will prepare you for when you are doing research as a mathematician and you will have someone standing behind you with a watch telling you that you have 50 minutes left.

Actually, I'm a physics major. :-p

Maybe the guy's watch will break or be in a time dilation field that will slow down his time compared to mine by a factor of 10^2.
 
  • #9
206PiruBlood said:
Do you think your instructor would allow you to come to class early to start the exam? When I took differential equations my instructor designed the exams so the students could actually finish in the time allotted. So long as we knew the methods, the questions were fairly straight forward. For example, solving a problem using variation of parameters could easily be a page of tedious calculations or relatively simple depending on the homogeneous solution. Whether the solution is long and tedious or simple, the student requires knowledge of how to employ variation of parameters.

Although even with this, only on rare occasion did somebody finish during class.

Yeah, VP and IF were in the first six problems. They were fairly straightforward since I knew the simple formulas for the methods. One of the problems required to find the time of death. He gave the rate of change of T. Fortunately, I remembered the algebraic equation for T and calculated k, but no calculators were allowed so I left it as ln (4/5). Heh. I actually wrote t as ln (4/5)/ ln (5/8), or whatever the numbers were. Technically, the answer would be midnight - t = time of death. There's probably a way to find the actual numbers, but I didn't figure it out at the time of the test. The longest one was a mixing rate problem. That was the last one I completed. I was a bit iffy on that one too at first then plowed through it as quickly as I could.
 

FAQ: Took my first diff. eq. exam this morning

What is a differential equation?

A differential equation is a mathematical equation that describes the relationship between a function and its derivatives. It is commonly used to model natural phenomena in fields such as physics, engineering, and economics.

What types of problems can be solved using differential equations?

Differential equations can be used to solve a wide range of problems, including growth and decay, motion, electric circuits, chemical reactions, and more. They are particularly useful for modeling systems that change continuously over time.

How do you solve a differential equation?

The process of solving a differential equation depends on its type and order. Generally, it involves finding the general solution using integration techniques and then using initial conditions to determine a particular solution.

What are some common techniques for solving differential equations?

Some common techniques for solving differential equations include separation of variables, integrating factors, substitution, and Laplace transforms. Each method is suited for different types of equations and can be applied to find both analytical and numerical solutions.

How can I prepare for a differential equations exam?

To prepare for a differential equations exam, it is important to review key concepts and practice solving various types of problems. It can also be helpful to work through past exams or practice problems, seek help from a tutor or study group, and clarify any confusing topics with your professor or classmates.

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