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Basic Trigonometry
4

Basic Trigonometry

Basic Trigonometry

(OP)
i graduated college in 2010. I recently passed my PE exam. Things are going as planned. Except that I have become trigonometrically challenged...let me explain

During school I could solve truss member forces (or any trigonetric problem) without even thinking. Now, I have to draw a triangle, then slowly draw complimentary and supplementary angles, then "Soh cah toa."

Is this the slow beginning of a mid-life crisis? I am tempted buy some educational computer game targeted to 8th graders so I can become more intimate with trig again. Any suggestion on game titles?

The part that really boggles me is that I use trig nearly everyday, but I have never used calculus during my career and I remember random derivatives and integrals like they are tattooed on the back of my eyelids.

I am too young for Alzheimer's. Can someone please tell me that I am not the only one suffering from lack of trigonetric identity.

In all seriousness, have you lost your previous quick-wittedness in areas before? What did you do, if anything?

Thanks in advance, this really is bothering me.

RE: Basic Trigonometry

When you are in a position to use such capabilities on a routine basis, you'll see that it returns quickly. Much like riding a bicycle! However, on the opposite side, if you don't use it you lose it.....cliche festival over!

RE: Basic Trigonometry

swiver - Don't worry about it too much. Professionally, over time you will gain more than you lose.

"Knowledge is gathered from learning and education, while most say that wisdom is gathered from day-to-day experiences and is a state of being wise. Knowledge is merely having clarity of facts and truths, while wisdom is the practical ability to make consistently good decisions in life."

A quote from this website:
http://www.diffen.com/difference/Knowledge_vs_Wisd...

www.SlideRuleEra.net idea
www.VacuumTubeEra.net r2d2

RE: Basic Trigonometry

Take a look at Khan Academy and what they have on trig. I think it is well done and free.

RE: Basic Trigonometry

There is always flotsam in the tide of knowledge. Some washes up quickly on the shore to stay. Some takes a little longer to get there. Some never makes it, winding up in the dead zone. It's part of being human.

Mike McCann, PE, SE (WA)


RE: Basic Trigonometry

If you remember soh coh toa [post edited to correct typo that later posts refer to] then what the hell else do you need? I've never used any of the (seems like) dozen other functions, half angle formulas, etc. When I used that esoteric crap in college I got it wrong more often than it helped. In real life (and I've been out of college 35 years) you'll never be able to explain elegant arithmetic to employers/clients anyway but most of them can remember having known sines, cosines, and tangents. I wouldn't worry about it.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

RE: Basic Trigonometry

I had to look up the quadratic equation at work today. Didn't bother me much, as long as I know it exists and how to use the equation; actual memorization and being able to recall everything from high-school and college doesn't matter much in practice.

Maine Professional and Structural Engineer. www.fepc.us

RE: Basic Trigonometry

Today, with the internet, there's even less need to memorize things. Moreover, there's a truckload more references that can be accessed, compared to the days of books and paper. If anything, there almost too much of some things, and not enough of others, but that's just the nature of useful knowledge.

TTFN
FAQ731-376: Eng-Tips.com Forum Policies
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Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers


Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
There is a homework forum hosted by engineering.com: http://www.engineering.com/AskForum/aff/32.aspx

RE: Basic Trigonometry

My use of trig over the years has been unrelated to triangles, so I too would need to recite soh/cah/toa given an angles problem. Usage.

I do have the curves burned into my mind though and the small angle approximations (sinx->x, cosx->1-0.5x^2, tanx->x) are instantly available.

All those sum/difference/half/double angle identities are on paper only.

For triangles, the sine rule is easy to remember, but I couldn't write down the cosine rule without help.

Steve

RE: Basic Trigonometry

(OP)
Thanks everybody.

Glad to hear that I am not the only one.

RE: Basic Trigonometry

I'm sorry, what is "soh coa toa"?

Good luck,
Latexman

Technically, the glass is always full - 1/2 air and 1/2 water.

RE: Basic Trigonometry

2
@Latexman

It's "soh cah toa" which is a mnemonic device used to remember the formula to compute the sin, cos, tin of any angle in a right triangle.

SOH means sin= Opposite (over) Hypotenuse or sin(theta)=(length of opposite side)/(length of hypotenuse)
CAH means cos= Adjacent (over) Hypotenuse
TOA means tan= Opposite (over) Adjacent

It's a memory device I believe I learned in grade 8 or 9.

_________________________________________
NX8.0, Solidworks 2014, AutoCAD, Enovia V5

RE: Basic Trigonometry

I wouldn't worry about it. So long as you remember your SO's birthday and, if applicable, your anniversary, you'll be fine.
To this day, I have to look up < and > when doing formulas. I don't know why, but I just completely blank on which is which.

Jeff Mirisola, CSWE
My Blog

RE: Basic Trigonometry

JNieman,
That is what I love about this site. When I (or anyone) screws something up, people will not hesitate to politely correct the record. If I'd made that mistake on Facebook, the few people there that would have a clue what I was talking about would have been questioning my ancestry. Thanks for setting the record straight, it really was just a typo.

I learned it in 9th grade as "Chief Soh Cah Toa" and something about adding the silly "Chief" has stuck with me for nearly 50 years.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

RE: Basic Trigonometry

"Alligator eats the bigger number" is the mnemonic I remember for greater than and less than symbols.

Maine Professional and Structural Engineer. www.fepc.us

RE: Basic Trigonometry

Every once in a while I'll stumble across some of my college homework and think "I did this? I must have been smart back then."

RE: Basic Trigonometry

I remember the cos and sin because I always visualize the cos graphically (on 360 deg circle) : In fact If I want to know the x component of a vector I use the cos - that I can remember always. I take it from there and so by deduction I know the rule for sin. I cannot remember any formula unfortunately :)

I can do addition, multiplication ... the basic stuff so to stay. More than these fundamental operations...mmm well I guess you need to be very sharp... ;)

RE: Basic Trigonometry

I'm rarely more than 2 ft away from either Mathcad, Excel, my HP15, or my phone with RPN-emulation calculator.

TTFN
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[IMG http://tinyurl.com/7ofakss]
Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers


Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
There is a homework forum hosted by engineering.com: http://www.engineering.com/AskForum/aff/32.aspx

RE: Basic Trigonometry

I use CAD to figger out all my triangles. What is trigonometry? I even use CAD to figure areas under curves and instantaneous curve slopes so I can avoid calculus too.

RE: Basic Trigonometry

I have to admit, if I have a CAD application open, I often won't bother with a Pythagorean equation. So spoiled, I am. *click, taptaptap, click* *writes down number*

_________________________________________
NX8.0, Solidworks 2014, AutoCAD, Enovia V5

RE: Basic Trigonometry

My 13 year old granddaughter asked me why she needs to know algebra and trig. I am NOT going to have her read this thread. Do CAD in lieu of trig? Heresy (although I've done it too).

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

RE: Basic Trigonometry

Oh, nobody reading this should think they wasted time learning it. What they did waste time on was wrote memorization. As long as you KNOW that triple integrals exist, and know that if you had to sit down and google a little you could do one, then you're good to go. I will never understand primary education's fixation on memorization of stuff that should be looked up.

Maine Professional and Structural Engineer. www.fepc.us

RE: Basic Trigonometry

2
"I will never understand primary education's fixation on memorization of stuff that should be looked up."

Follow through with a look up spell check on wrote vs rote. Rote memorization taught me that.

RE: Basic Trigonometry

I'm committing everything to memory so when I'm sucked into a time warp and sent back to the 18th century, I will be a scientific GOD! Muhahahahhaaaaaa bigglasses

Dan - Owner
http://www.Hi-TecDesigns.com

RE: Basic Trigonometry

Dan,
I like your evil plan. I bet LED lighting would be a big hit in the 1700's.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

RE: Basic Trigonometry

I don't think I solved even one differential equation by hand even in grad school. I understood them but if I ran into something non-trivial, I fell back on my TI-89 or some software package. Looking back, I think a lot of my math classes were taught kind of backwards. When I took calculus, they just kept throwing different methods for integrating equations at you. If I taught the class, I would start with and spend more time on being able to interpret and understand the results from an integral than spending so much time on methods of integration.

RE: Basic Trigonometry

I think it's a good idea to have some things memorized. Would you really want to go to your doctor and instead of them saying "you have measles" they say "I remember reading about this, let's google it and see what you have". Same thing in engineering, who do you have more confidence in? The person who knows stuff off the top of their head, or the person that googles it and sends out an email later.

RE: Basic Trigonometry

"Same thing in engineering, who do you have more confidence in? The person who knows stuff off the top of their head, or the person that googles it and sends out an email later."

If I asked an American structural engineer "Is a W10x22 a standard beam size?" and they gave me any response other than "Yes" then I'd have no confidence in them.

If I asked a structural engineer "What size beam do we need here?" and the response was that they'd get back to me on that shortly, I'd understand, though. Some will be able to look at a situation and say "You'll be fine with a C10x15.3 at 5' spacing" off the bat and be fine, but some will care to crunch a few numbers first and I wouldn't begrudge either their answer.

_________________________________________
NX8.0, Solidworks 2014, AutoCAD, Enovia V5

RE: Basic Trigonometry

The really good engineers I know/have known seem to have a lot of this stuff in memory and can do quick feasibility calcs in their head etc.

Whether the memorization is what makes them really good I'm not sure of but there is some correlation.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Basic Trigonometry

GAHH!!! [At my typo and BUGGAR's hilarious comment on it.]

Point taken, obviously some things need to be memorized. Spelling and grammar obviously among them. That said, I still feel most of the STEM fundamentals we learn in primary school don't need to be memorized to be effectively used. Memorization should happen through repetitive use or need to use them quickly without reference (survival skills for example). I remember SOH CAH TOA because I use it quite often, I don't remember how to hand calculate a stiffness matrix because I haven't done one since college. But I know how it works and know how to apply them.

Maine Professional and Structural Engineer. www.fepc.us

RE: Basic Trigonometry

My son has no problem with this sort of scenario. Most math he learns vaporizes after the class is over. What a PITA, since his next class is usually based on the foundations taught in the previous class.

"most of the STEM fundamentals" does not equal "stiffness matrix"

I think there are "fundamentals" that should be ingrained, because the subsequent information cannot be readily understood without understanding the fundamental materials. Memorizing stiffness matrices just makes you more of a nerd... winky smile

TTFN
FAQ731-376: Eng-Tips.com Forum Policies
[IMG http://tinyurl.com/7ofakss]
Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers


Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
There is a homework forum hosted by engineering.com: http://www.engineering.com/AskForum/aff/32.aspx

RE: Basic Trigonometry

Those should be separate arguments; "most of the STEM fundamentals we learn in primary school don't need to be memorized to be effectively used" is separate from my point about "memorization should happen through repetitive use or need to use them quickly without reference." Obviously a stiffness matrix is not a fundamental mathematical concept.

I'd also revise my statement to replace "most" with "many". Many fundamentals don't need to be memorized; "most" was too broad and misleading from my intent. Obviously certain fundamentals need to be memorized and repeatedly refreshed if they are needed again but easily forgotten (as appears to be your sons case). Everyone needs to know 2+2=4 to get through daily life, most people memorize this because they use it often. This was the point that I was trying to make; if a skill is useful it will become memorized, or at least an attempt will be made to memorize it.

I'm not saying that people shouldn't have memorized some basic facts of science, math, language, history, and so on. My point was that there are many aspects of the skills we learn in education that are taught and tested from memory alone. Obviously memorizing something makes it easier to prove you learned it but it doesn't accurately reflect what should be learned in my opinion; the existence, application, and usage of the fundamental skill being taught. Thus, the fact that most people forget much of what they memorized in school seems justified.

Maine Professional and Structural Engineer. www.fepc.us

RE: Basic Trigonometry

For me, it's a sin of insufficient ram.

RE: Basic Trigonometry

I have plenty of RAM... my problem is I have a 64-bit memory and a 32-bit addressing system :-/ And my control lines are flaky, along with the occasional brown-out.

Dan - Owner
http://www.Hi-TecDesigns.com

RE: Basic Trigonometry

My parents taught me never to cosine anything, but perhaps I'm off on a tangent.
I try to do trigonometry, but, see? can't.

RE: Basic Trigonometry

Snorgy...sounds like MBA influence to me!lol

RE: Basic Trigonometry

SNORGY, sounds like you're high on pot 'n use too much.

_________________________________________
NX8.0, Solidworks 2014, AutoCAD, Enovia V5

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