Question

I have a trig final tomorrow and transformations always kick my butt.
I understand changing everything to sine and cosine, are there any tips to "see" relationships faster or to generally improve your time and success?

Answer 1

Or is there a "dummy's guide" of steps?

Answer 2

What do you mean by transformations?

Like given a function \(\large y=2\sin(3x-4)+5\) and being asked to graph it?

Answer 3

No, more like:
Find theta if 0</= theta</= tpi and tan^2 theta - sec theta -1 = 0.

I finally figured the answer to that one.

Generally solving for theta when you start with garbage so that you can factor or use quadratic in order to graph.

Answer 4

Ah I see :)

Answer 5

Graphing it once I have a common value is not a problem it is getting cot, sec, csc sin mises to one form

Answer 6

"mixes"

Answer 7

Another transformation example might be:
Prove sec (A+B = cos (A+A)/cos^2-sin^2.

These types of problems in geral are a pain.

Answer 8

Well this might seem rather basic, but for recognizing relationships make sure you really really are familiar with the `Square Identities`.

sin^2x+cos^2x=1
tan^2x+1=sec^2x
cot^2x+1=csc^2x

Getting really comfortable with those will definitely help to notice when it's easier to manipulate a square rather than the secant in the problem.

Also keep the `Sine Double Angle Formula` in the back of your mind, that one seems to pop up quite a bit.

sin(2x)=2 sinx cosx

Answer 9

Hmmm that's a weird one.. D:

Answer 10

Is that an actual problem? :D lemme see if i can solve it.

Answer 11

"I meant cos (A+B)" but that was just an example

Answer 12

Ah I see :)

Answer 13

Yes the last one was a real problem, I don't need to do it any more, but I looked it up.

Answer 14

I guess I just need to work harder on memorizing the basic identities...

Answer 15

Final is tomorrow? :( hmm..

Trig is my favorite subject.. but it seems to be a tough one for a lot of people.
You really have to give yourself a lot of prep time to memorize formulas.
There are just soooo many formulas to remember.

Answer 16

Some of the stuff we are doing in trig the tutor said he didn't see it until calc 3. I lover trig and what you can do with it, I am just too new to it and my placement test put me past algebra which I never had...

Answer 17

Oh a bit rusty on the algebra? Mmm darn :c