Is trig needed for Cal I - III?

[fractals]

I took a LONG break from school and stopped at college algebra. I am taking Pre-cal during this summer, but they skipped over any trig in the book since its a short 6-week session. I have a choice in taking Cal next semester, or taking Trig.

 

I know the very BASICS of trig, such as what sin/cos, etc are from a triangle, but none of the identities, circle units, etc. Some of my peers say that a trig course isnt needed, and that I can learn myself. Is this true? Right now I am undecided what is best for me. I had a hard time doing polar coordinated in precal because of the basic trig. Other than that, I have an A in the course(i have final next week).

 

So...should I take trig? Or continue on to Cal and learn trig by myself? I have to take Cal I - III. I am a CS major.

 

please any input....

 

BTW, Trig was a pre-req for pre-cal...but I took pre-cal at a community college before and got a D, thats why they allowed me to take pre-cal without trig at the university.

[Shamand007]

Having taken college calculus, I would say that you should know at least the basic properties of trigonometry. They aren't hard to learn and it doesn't take much time to do so. You don't need to know advanced concepts of trig; you'll learn those in calculus itself

[Reaper]

For calculus, you would want to know: Basic trig ratios, Basic trig functions (e.g. y = sin x) and their transformations, and basic trig identities such as (sin x)^2 + (cos x)^2 = 1.

 

 

You should probably get a textbook on Trig if you don't feel you know a whole lot, so that you can catch up and go over it quickly.

 

I would suggest getting "Just-in-Time Algebra and Trigonometry" 3rd Edition by Guntram Mueller and Ronald I. Brent. I have their second edition, but that was written quite some time ago. Their books is very user-friendly, breaks down concepts so that they could be easily understood, and you can go through it very quickly. It is also great for review too.

 

You can get it on Amazon

[Royston]

I'd say at the very least you need to understand trigonmetric ratios, unit circles et.c before you start calculus, that's just my opinion, but trig crops up in calculus a lot, so I'd recommend becoming familiar with the concept and memorize the identities.

 

As above (what Lockheed touched on) here's a brief summary...

 

Take P(x.y) as a point on a unit circle, with centre O, where the angle from the positive x axis to OP is theta [math]\theta[/math] it's important to remember if [math]\theta[/math] is positive you're measuring the angle anticlockwise, and obviously if [math]\theta[/math] is negative you're measuring in a clockwise direction, so...

 

cos [math]\theta[/math] = x and sin [math]\theta[/math] = y

 

where tan [math]\theta[/math] = sin [math]\theta[/math] / cos [math]\theta[/math] obviously under the condition cos [math]\theta[/math] doesn't equal zero.

 

Useful identities...

 

cos (-[math]\theta[/math]) = cos [math]\theta[/math]

sin (-[math]\theta[/math]) = -sin [math]\theta[/math]

tan (-[math]\theta[/math]) = -tan [math]\theta[/math]

cos ([math]\frac {1}{2} \pi - \theta[/math]) = sin [math]\theta[/math]

cos ([math]\pi - \theta[/math]) = -cos [math]\theta[/math]

sin ([math]\pi - \theta[/math]) = sin [math]\theta[/math]

tan ([math]\pi - \theta[/math]) = -tan [math]\theta[/math]

sin ([math]\frac {1}{2} \pi - \theta[/math]) = cos [math]\theta[/math]

cos ([math]\theta + 2\pi[/math]) = cos [math]\theta[/math]

sin ([math]\theta + 2\pi[/math]) = sin [math]\theta[/math]

tan ([math]\theta + \pi[/math]) = tan [math]\theta[/math]

cos^2 [math]\theta[/math] + sin^2 [math]\theta[/math] = 1

 

Once you have unit circles down, you can move onto functions using trig...e.g f(x) = tan x et.c, these won't make much sense unless you understand unit circles.

[abskebabs]

If you want to learn trig the best way to do it for the long run IMO, is to prove the identities so they make sense to you and then memorise them. It might be good to just skip and memorise them(especially if you're in a rush), but I think proving them or at least appreciating why they are valid gives you some context in which to remember them, and more importantly; try to gauge some meaning.

 

Admittedly, it will be pretty hard for you to come up with a proof on your own(though impressive if you do), but if you'd like; I know one for the addition of angles of cosine, sine and tan, so PM me if you'd like me to tell you it in more detail.

 

I guess I'm just feeling too lazy to make a thread on it:cool:

[Royston]

If you want to learn trig the best way to do it for the long run IMO, is to prove the identities so they make sense to you and then memorise them.

 

Counter to what abskebabs is saying, proofs won't give you a better understanding of the subject...proofs are actually a different concept altogether,

 

I'd quite happily give you the proof of integration for example, but I'm not sure it would help in your understanding of the subject...i.e become familiar with the operations, AFAICS proofs can wait.

 

EDIT: Ummm, ignore my last comment... quite late, had a number of drinks, so I misread abskebabs post.

[hatsoff]

I took a LONG break from school and stopped at college algebra. I am taking Pre-cal during this summer, but they skipped over any trig in the book since its a short 6-week session. I have a choice in taking Cal next semester, or taking Trig.

 

I know the very BASICS of trig, such as what sin/cos, etc are from a triangle, but none of the identities, circle units, etc. Some of my peers say that a trig course isnt needed, and that I can learn myself. Is this true? Right now I am undecided what is best for me. I had a hard time doing polar coordinated in precal because of the basic trig. Other than that, I have an A in the course(i have final next week).

 

So...should I take trig? Or continue on to Cal and learn trig by myself? I have to take Cal I - III. I am a CS major.

 

please any input....

 

BTW, Trig was a pre-req for pre-cal...but I took pre-cal at a community college before and got a D, thats why they allowed me to take pre-cal without trig at the university.

 

Unlike these blokes, I was actually in your position. I took Calc II in high school, aced the BC AP test, and never bothered with math again. Then I sort of ran off into drugs and alcohol for nine years or so, and only recently came back to it. I *just* finished taking Calc 1 as a refresher course.

 

Do you need trig?

 

Yes and no. Yes, you really need to re-learn it, but, no, you don't need to take a class on it. Remember, trig was just a unit in Geometry, and you learned more about it in Algebra 2 and Calc 1. But it was never its own class.

 

The identities are helpful, but unnecessary. Just remember the good ol' Pythagorean Theorem. That's the basis of all identities, anyway. But you should learn them, regardless.

 

Just remember, you don't *need* to re-take trig, but you *will* need to re-learn it some way, usually online. So be ready.

[Bignose]

Sometime in Calculus II you will be introduced to a technique termed 'Trigonometric Integration' where you will substitute trigonometric functions for the variables in the integrand. And, the idea is that the trigonometric functions are easier to manipulate, i.e. via angle sum rules, angle product rules, etc, than the way the original integrand was written. You will need to know the trig functions forward and backward to pass this part of the class. So, there is a part of calculus where the trig functions are an absolute necessity.

 

However, I do agree with the other posters that you can in all likelihood teach yourself all the necessary information. Another option, at least what I did at my undergrad institution, was a week-long trig review class one week before classes started. Something like that might be perfect.

[fractals]

thanks for your opinion guys. im going to take trig just to get good at it...because i probably wont devote a lot of my time studying on my own. im also taking linear algebra as well this semester, which is required. I still think discrete math/graph theory was harder than those courses. I strugged in that class...but ended up wih a B.

 

Like I said, im a CS major and a math minor...the only reason I am minoring in math is because I would only need a couple of more classes in my CS degree plan to get my minor.