# Math Help - Trig test tomorrow. please, please help!

1. ## Trig test tomorrow. please, please help!

Ok, so I have a test tomorrow. My teacher is an Algebra teacher and doesn't really know how to explain Trig all that much, so all of us in her class are a little confused. I went in for help, and I really just don't understand any of it. It seems like I understand it more when someone else explains it, so if someone could help that'd be amazinggg.

A: It says determine the coordinate point. I know that that means either (√2/2, √2/2), (1/2, √3/2), or (√3,2, 1/2) and I know that those coordinates corresponds to it being pi/3, pi/4 or pi/6 but how do I know if it's negative or positive and what quadrant it's in?

B: How do you evaluate a trig function?
Example: sin 7pi/2

C: The question is find cotO, if cscO=6, with O in quadrant II
Then it says for another similar question, csc^2 121^0 -cot^2 121^0

D:Find the remaining trig functions given sinO = 1/√3 and cosO=5/√3
(I do this like Pythagorean theorem right?)

Thank you sooo much to whoever answers these. You can answer one or all of them, it doesn't matter. Any help I can get is amazing. Thank you

2. ## OK

A: It says determine the coordinate point. I know that that means either (√2/2, √2/2), (1/2, √3/2), or (√3,2, 1/2) and I know that those coordinates corresponds to it being pi/3, pi/4 or pi/6 but how do I know if it's negative or positive and what quadrant it's in?

You have to understand what it means to take the sine value of an expression like $\frac{\sqrt{2}}{2}$ If you draw the points in a cordinate system you will understand it.
For example, evaluate the $sin$ $\frac{\sqrt{2}}{2}$
What are you doing? You are calculating the opposite/hypotenose. do you understand what the $\sqrt2$ part represents?
Where can it be if it is positive/negative?

B: How do you evaluate a trig function?
Example: sin 7pi/2

Remember one complete circle is $2\pi$.
$7/2 = 3.5$ and since sine function repeats itself after each circle that means you can substract one circle $2\pi$. Leaving you with $1.5\pi$

C: The question is find cotO, if cscO=6, with O in quadrant II
Then it says for another similar question, csc^2 121^0 -cot^2 121^0
What do you mean $(csc^2(121^0))$?

D:Find the remaining trig functions given sinO = 1/√3 and cosO=5/√3
(I do this like Pythagorean theorem right?) are you sure you got everyting right on this one? Or.. are these sin0 and cos0 two different angles/questions?

Any more specific questions just ask..good luck at your exam.

3. Hi, thanks for replying

A: I'm given a unit circle with the different coordinates on them. But since it only has things like pi/4, 2pi/3 and so on, im confused at how to find things like -13pi/6 and -15pi/3, the exact question was "determine the coordinate point at the indicated distances from A". I hope that makes a little more sense.

B: that helps a lot! but how would that differer if it was tan, cos, sec, csc, or cot.

C: Im not really sure. that's what the question says. it says Evalute. And the question just says: csc^2 121^0 - cot^2 121^0
Im not really sure what it's asking me to do.

D: they're dwo different angles, and I'm given a blank triangle to help, but it's all the same problem.

Thank you