Thread: 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

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 If you draw the points in a cordinate system you will understand it.
For example, evaluate the
What are you doing? You are calculating the opposite/hypotenose. do you understand what the 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 .
and since sine function repeats itself after each circle that means you can substract one circle . Leaving you with

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 ?

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.

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