Basic Trigonometry 4

[appot]

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.

 

[Ron]

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!

 

[SlideRuleEra]

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_Wisdom

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[magoo2]

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

 

[msquared48]

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)

 

[zdas04]

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

 

[TehMightyEngineer]

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.

http://www.fepc.us

 

[IRstuff]

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

Need help writing a question or understanding a reply? forum1529


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

 

[SomptingGuy]

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

 

[appot]

Thanks everybody.

Glad to hear that I am not the only one.

 

[Latexman]

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

Good luck,
Latexman

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

 

[JNieman]

@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

 

[JMirisola]

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

 

[zdas04]

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

 

[TehMightyEngineer]

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

Maine Professional and Structural Engineer.

http://www.fepc.us

 

[spciesla]

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."

 

[rotw]

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...

 

[IRstuff]

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

TTFN
faq731-376

Need help writing a question or understanding a reply? forum1529


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

 

[BUGGAR]

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.

 

[JNieman]

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