Finding domain & range of trig functions

[harmonii]

Hello: I'm in Calculus I this semester in college and I seem to have forgotten the method for finding the domain and range for trig functions. I'm currently wrestling with 2 different problems related to domain/range:

PROBLEM #1:
Instructions: Find the domain and range of the function

Problem: f(t) = sec pi(t)/4

PROBLEM #2:
Instructions: Find the domain of the function.

Problem: g(x) = 2 / 1 - cos x

I'm not even sure where to start with these problems. I know the domains of all the trig functions (sin & cos is every angle theta, tan & sec is every angle theta except pi/2 + pi(n), etc.) but I can't apply this knowledge to figuring out these problems. I'm feeling a bit hysterical at this point, because I know I should already know this. Any help is appreciated.

 

[tkhunny]

Are you looking for steps and procedures? You will not particularly find any. These are thought and definition problems.

Domain and Range of cos(t) is? [Real Numbers] and [-1,1]
The cosine is zero (0) at \(\displaystyle \pi/2 + k\pi\)

Contemplate
cos((\(\displaystyle \pi/4\))t) Where is this expression zero (0)?

Now take another look at "Problem #1".

 

[harmonii]

Are yo ulooking for steps and procedures? You will not particularly find any. These are thought and definition problems.

Really, what I'm looking for is a method. Whether that method is a set of steps and procedures or a thougt process doesn't matter.

Contemplate
cos((\(\displaystyle \pi/4\))t) Where is this expression zero (0)?

You know, I have no idea, and as I go through my homework I'm finding more and more that I'm unsure about. It looks like I'm going to need to spend a few days seriously studying the trig tutorials on the web. (Suggestions anyone?)

What I just don't understand is how I could have forgotten so much in just 3 months! I mean, I struggled with the trig portion of my pre-calc class, but I still managed to fetch a B in the class. Now I can't even answer what I know are simple questions.

At any rate, thanks for trying to help.