Hi there.(adsbygoogle = window.adsbygoogle || []).push({});

I'm really confused with this question, it's about the unit circle.

Firstly I was asked to look up the values of (sorry I don't know how to put in the symbol for PI-3.14) 'cos(PI/3)' and 'sin(PI/3)' ok I got them.

Then I'm told to use the unit circle diagrams (diagrams?) to show the connection between:

cos(2PI/3), sin(2PI/3) and cos(PI/3), sin(PI/3)

(Then again for cos(4PI/3), sin(4PI/3) and cos(PI/3), sin(PI/3)

What is confusing me is the 'sin' and 'cos'! I don't understand where they fit into the unit circle?? I can find 2PI/3 on the unit circle, but how do I know if it is for sin or cos??

And by connection, I firstly thought, 'Ok, PI/3 and 2PI/3 are basically both 60degrees from the positive y axis' but then that isn't right because I haven't considered cos or sin!

If someone could point me in the right direction, it would be a huge relief!

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Help with the unit circle please.

**Physics Forums | Science Articles, Homework Help, Discussion**