Most Frustrating, Embarrassing Brain Farts

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SUMMARY

This discussion revolves around the common experience of making fundamental mistakes in mathematics, particularly in physics and calculus. The original poster, identifying as a "physics guru," shares a personal anecdote about struggling to integrate a velocity-dependent force equation, m(dv/dt) = Cv², due to a momentary lapse in understanding. Participants reflect on similar experiences, highlighting errors such as misapplying logarithmic properties and incorrect simplifications, emphasizing that even those with advanced mathematical backgrounds encounter these frustrating "brain farts."

PREREQUISITES
  • Understanding of basic calculus concepts, including differentiation and integration.
  • Familiarity with physics principles, particularly Newton's laws and force equations.
  • Knowledge of logarithmic properties and their applications in mathematical problems.
  • Experience with algebraic manipulation and simplification techniques.
NEXT STEPS
  • Study the integration of differential equations, focusing on variable separation techniques.
  • Review common pitfalls in logarithmic identities and practice correcting them.
  • Explore advanced calculus topics, such as the application of the chain rule in differentiation.
  • Engage in problem-solving exercises that emphasize algebraic manipulation to reinforce foundational skills.
USEFUL FOR

Students in high school or college-level physics and mathematics courses, educators teaching calculus and physics, and anyone interested in improving their problem-solving skills in these subjects.

Jilvin
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I am a "physics guru", at least at my high school's level (which isn't really anything at all). I know several advanced integration techniques, linear algebra, and fairly advanced methods for solving differential equations. Even with all of this mathematics background, I still have not taken the AP Physics C exam due to my school's (in my personal opinion) lax curriculum not offering it as of now.
So, with my 8 dollar "University Physics" book, I scanned through to the "challenge problems" (which only take about a minute or two of thought to complete). One of the problems had me analyze certain properties of the equation (showing a velocity dependent force):

m(dv/dt)= Cv2

So, with all my arrogance and background, I tackled this problem. However, I soon became infuriated by the fact that I could not integrate the RHS with respect to time! I drastically manipulated differentials, but it was of no use! This simple problem had stumped me!

Then, about an hour after I had given up in despair, I realized that the left hand side of the equation existed and that I could divide by the v2 term to separate the variables. Wow. Just... wow. Does anybody else have these discouragingly terrible brain farts?
 
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oh you I answered my age wrong ...twice -_-
I think I can think of e=mc^2 faster than my age xD
 
I think everyone has used a property of logarithms wrong at least once in a long, complicated problem and had to retrace their steps until they saw the boneheaded nonsense log(a + b) = log(a)log(b) in some dense block. Or maybe that's just me. :p
Also, 2 + 3 = 6, of course.
 
My theory is that 10% of all differentiations end up as integrations and 10% of integrations end up as differentiations.:cry:.It's sort of like a mathematical uncertainty principle.
 
Have you never canceled out 2s?

\frac 2 2 = 0
 
Borek said:
Have you never canceled out 2s?

\frac 2 2 = 0

:smile:
 
:redface:...:shy:...:frown:......:mad:...:devil:----- Get it?! :biggrin:
 
  • #10
Borek said:
Have you never canceled out 2s?

\frac 2 2 = 0

I probably have. I know for sure I did this once on a test:

(x + y)3 = x3 + y3

:redface:
 
  • #11
Can't we talk about our infallible moments of lucid insight instead? Much shorter list.
 
  • #12
[PLAIN]http://profile.ak.fbcdn.net/profile-ak-snc4/object2/1868/74/n190172509102_8960.jpg
[PLAIN]http://www.freewebs.com/fos08/Jokes/funny%20maths%201.JPG
[PLAIN]http://haha.nu/files/uploads/farm1.static.flickr.com/170/371722884_a8d1da8f44_o.gif
 
Last edited by a moderator:
  • #13
http://www.woosk.com/wp-content/uploads/2009/05/whale.jpg
 
  • #14
Borek said:
Have you never canceled out 2s?

\frac 2 2 = 0

Way too many times...
 
  • #15
lisab said:
I probably have. I know for sure I did this once on a test:

(x + y)3 = x3 + y3

:redface:


Eek!:smile:

Then again, I can't even recall the last time I sat for a test that even remotely asked a question like that.
 
  • #16
lisab said:
I probably have. I know for sure I did this once on a test:

(x + y)3 = x3 + y3

:redface:

Of course, one of x or y was 0, right? :-p
 
  • #17
PracticeFish said:
Of course, x=y=0, right? :-p

x=-y

PS: Hey! You did it actually in the thread!
 
  • #18
Upisoft said:
x=-y

PS: Hey! You did it actually in the thread!

Damn, me too. There are 2 more solutions:
x = 0 and y = 0
 
  • #19
I was asking you all for your personal worst brain farts, but posting complete nonsense is also fine I guess.
 

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