What the **** is trig?

[ZeroPaladn]

I've seen countless time in programs made by advanced programmers things such as cos, sin, tan, cosd, ect... what do they all mean and how do you use them?

[codemage]

It's a type of math (geometry) that deals with angles.

When you learn about it first in school, the various functions tell you what the angles in a triangle are if you know the length of the sides, or vice-versa.

As you continue, you learn that it applies to all sorts of stuff, from electronics to physics to optics to art.

[Andy]

trigonometry: the study of triangles

you should've learned simple trig in grade 10 and 11.

[Delos]

Trigonometry is a mathematical study of angles and their functions, specifically with reference to triangles. Triangles happen to be really neat little geometric objects, and are very, very regular.
For instance, the sum of all angles in a triangle is 180 degrees. Want a cool test? Cut out a triangle on a piece of paper (make sure it has straight edges). Then snip off its edges and line them up - they'll make a perfectly straight line.

When it comes to programming, trig is used primairly for calculating movement - in many forms. For instance, if you have a dot moving across the screen, you may not want to limit yourself to moving in purely horizontal or vertical directions.
Trig will allow you to calculate the value of each of your (x, y) vectors so that you might achieve angled motion.
More advanced stuff will allow you to play with 3D type-graphics.

To start yourself off, find out what SOH-CAH-TOA is. Once you have that down, try to apply those concepts to breaking a triangle into its components - this will lead directly into angled motion, the simplest application of trig.
Post up your results when you're done.

Yes, I know was horribly vague in this post. That was intentional. Trig is far too detailed and extensive a topic to summarize in a post. Especially with the, uh, nebulous question you post.... The idea here is for you to teach yourself some very elementary maths. And if you're in Grade 11 physics, there is no way you're going to get anywhere unless you know basic trig.

[ZeroPaladn]

i wish. Took academic math grade 10 and financial math in grade 11. Taking grade 11 physics right now, and im confuzzled. Would someone care explaining?

[ZeroPaladn]

Ill post what i know right now.

sine (theta) = (length of opposite side/length of hypotnuse)
cosine (theta) = (length of adjacent side/length of hypotnuse)
tangent (theta) = (length of opposite side/length of adjacent side)

(sine of side A/angle A) = (sine of side B/angle B)

C^2 = A^2 + B^2 - 2AB cosine (theta)


thats all i know. formuals. dont know what any fot ehm mean, i just punch in the numbers.

[Bored]

Since you don't have the basic background in trigonometry It's going to be nearly immpossible to teach you through a post. My best suggestion would be to look up trigonometry on www.ask.com (great for infromational sites such as math and science help) or another search engine of your choice. Or if you don't want to learn yourself you should seek extra help from your teacher as trigonemtry concepts are largely built upon knowledge of other trig concepts and to get you up to par through a forum would be a tedious, time-consumming, strenuous task.

[cool dude]

firstly for grade 11 physics u hardly need to know anything about trig and since u know the formulas all u have to do is plug in the numbers simple as that so u shouldn't worry. taking financial math wasn't a bright decision because u should know math and that course doesn't teach u anything u didn't already know from grade 10 academic so that was a waste. if u really want to learn more about trig although u don't need it much for grade 11 physics u can go to http://aleph0.clarku.edu/~djoyce/java/trig/

[Delos]

cool dude wrote:

firstly for grade 11 physics u hardly need to know anything about trig and since u know the formulas all u have to do is plug in the numbers simple as that so u shouldn't worry

Oh, how we love plugging numbers into formulae! Sure you don't really need to know anything, I mean that would mean we'd be applying ourselves and actually attempting to understand our work beyond the obligatory scope of our courses! Heaven forbid!
Why stay ignorant when an option exists?

[Andy]

if you didnt have to use trig in grade 11 physics then you mustn't have learned very much...

[ZeroPaladn]

ive used trig in grade 11 physics, i just dont understand whats behind it. and thanks for the links and the ideas, time to teach what my grade 11 math class failed to do.

[TokenHerbz]

I once knew trig really well, a few years ago... i got 3rd highest (87%) in that class... It's amazing that i forgot everything... its only been 600 days :S

[Cervantes]

Trig is necessary for grade 11 physics, especially for all the first unit: motion.

Am I the only one that sees this as not Turing?

Moved to Off Topic.

[md]

Ahh trig... such a joy... The thing I hate about the current education system (and this applies especially to the way trig/calculus is taught) is that the emphasis is on you memorizing the formulas and less on you knowing when and where to use them. Were I given a list of formulas I'd be able to do fine on exams... but no; you gotta memorize all the f-ing inverses for trig functions and what their integrals are...

/me goes off to rant for a bit

Back on topic; the only thing I've ever used trig for in a programming type enviroment is writing physics sims. And even then there are ways of avoiding costly trig function calls (time-wise) with fairly accurate results.

[cool dude]

Andy wrote:

if you didnt have to use trig in grade 11 physics then you mustn't have learned very much...

i didn't say u don't use trig i said u hardly use it in grade 11 physics. yes u do use trig in grade 11 physics but the level of trig u need to know for grade 11 physics is grade 10 trig and that he should know.