So I am doing some Statics and Dynamics homework tonight and I keep getting an answer that does not jive with the back of the book. I work and rework the problem over and over for over an hour and keep getting the same answer.
I am convinced that my calculator is screwed up (FWIW the three angles in a tri angle were adding up top 194 degrees which is impossible). I am having a fit here because I can’t get the answer right and I am SURE I am doing it right. My calc MUST be messed up.
I call my dad in a rage at my POS calculator. If you are in an engineering program, or any math heavy program, you can agree with me that loosing faith in your calculator is almost on level with loosing faith in god. Without it you are screwed to a life of calculating arcsins by hand!! Once you loose faith you will always question your calculators answer. Even on tests!
So I am telling my dad, who made it thru junior college, that my calc is screwed, so I am screwed. I told him what I did, sure that he wouldnt understand (Sin rule to calculate missing angles). I told him that I used the Pythagorean Theroem to calculate the missing side of the triangle. He says to me “Its a right triangle right?”
I said “…shit…thanks dad”. It wasn’t and proceeded to start over and calculate an exact match to the answer in the back of the book.
For what its worth, the TI-89 rules the world of calculators, but only if you give it the right information.
And just remember, kids, the Pythagorean Theorem is just a special case of the Law of Cosines.
And even as a professor, I’d occasionally screw up by my calculator being set on degrees rather than radians, or vice versa. But like Stinkpalm says, I had the advantage over my students (who were taking precalc or Calc I) in that I knew the answers were garbage.
Calculator? Bah… Real mathS students don’t need them.
Not that I’m bitter that they won’t let us use them in our maths exam or anything. Really.
I too am the king of stupid errors. I mean, there was this one time when I was working on a problem with Filters and I applied the Eisenstein condensation theorem to get the dual-filter. It seemed like an easy way to demonstrate local compactness and thus get the required result by reduction of singularities. The proof kept falling apart halfway through though - There were closure issues for some of the semi-compact sets. Friend came along, took one look and said “You do know the space you’re applying it to isn’t Haussdorff, right?”. Boy did I feel stupid. *
Nah, seriously. I constantly mess up my arithmetic, and tend to make wild leaps of logic in proofs. 99% of the time they’re valid ones, but there are some really bad errors hiding in there as well.
RTFirefly: The law of cosines is just a special case of the distributivity of the dot product anyway.
There was absolutely no real maths in this statement.
My usual trick is the negative sign that goes MIA halfway through the problem, totally destroying my chances of getting a correct answer. I’ll get my test back with little red - signs all over it to show what a freakin moron I am.
Oh, and for anything that doesn’t involve graphing, matrices, or solitaire, it’s the TI-34 that rules the world of calculators. I’ve had mine since the seventh grade and it’s never led me astray.
Don’t you dare insult my baby (TI-83), Stinkpalm! She’s gotten me through high school AND most of my university math classes (for homework at least, since most of my classes didn’t allow them for tests)(Oh, and to play nibbles and tetris)!
[sub]Just don’t let her know that I’m secretly lusting after a TI-89. It’ll break her heart[/sub]
I would like to put in a good word for the TI-86, however I do believe I must say the TI-89 has spoiled me in some areas, such as solving functions. Luckily my Calc teacher never let me replace my legs with a wheelchair, forcing me to do all the work without a calculator as well - so I may limp when I walk in the realm of mathematics, but I can walk none the less.
Once you get into Advcanced Circuit theory and high end physics the rudementary calc is the least of your worries so the TI-89 is the bomb for checking yourself.
I use it 80% for the screen. It just plain rules. Worth the price of the calculator by itself.
20% for the sweet calc and DE that it can do.
32% for how easy it is to see if you inputted the equ correctly with the pretty print on.
OOPS. Bad math there. Musta done it on an 83
Nobody here gets to feel bad - try being a professional engineer and having a brain fart to the point of not being able to calculate simple angles and vectors? What’s worse is having that brain fart while you’re in the middle of a crusher project and where you’re the one being relied on for the ciritcal data - usually while there are various highly paid technicians waiting on your output.
It’s usually at those times that I realize it’s time to get away from the desk and have a coffee…
You might want to back up a bit and review some of your earlier materials. You see, the number 83, while a virtuous and round-looking specimen, did not appear in my post. It is the saintly and solar-powered number 34 of which I speak.
Okay, so I have a TI-86 too. But only for graphing, matrices and solitaire. Fie on the TI-83!