# How much Trig is Needed to suceed in Calc?

1. Nov 3, 2012

### zoiberg137

I am studying trig on my own in order to prepare myself for calculus. Just wondering how much I need to know. For example, would being familiar with the unit circle and inverse functions suffice, or should I thoroughly study every chapter of my trig book and know every concept to the best of my ability? My last prof said that in algebra there are some concepts which really aren't necessary unless you intend to do computer programming...So I thought maybe there are some similar scenarios with trig where certain concepts just are not going to apply to calculus and beyond.

I only ask because I would like to start studying calc on my own as soon as possible so that I'm confident when I start my class, but I don't want to get ahead of myself, even if it is only self study! :)

Thanks for you input!

2. Nov 3, 2012

### micromass

Trig is fairly important in calc, but you won't need to know every single detail.

The most important part of trig are the trigonometric functions and inverse functions. Especially the identities such as $\sin(2x)=...$ and $\cos(x)+\cos(a)=...$ are used a lot in integration.
When I say that those identities are important, that doesn't mean you need to memorize them and know how to prove them. The most important part is that you know the identity exists.

For example, if I want to integrate the function $\sin(x)\cos(10x)$, then this is not an easy task. If it were a sum instead of a product, then it would be easy. Maybe there exists a formula that transforms a product into a sum? Knowing that such a formula indeed exists is crucial.

Things like triangles, cosine rule and sine rule are not important at all in calc. I think you can safely skip that.

Last edited: Nov 3, 2012
3. Nov 3, 2012

### seaofghosts

One thing I've needed a couple of times so far is how to use the reference triangles. This is a trick you might not learn in self study, because everything is so unit-circle-oriented. But you can find everything by using reference triangles, and they're easy to sketch in the margins if you need them.

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