+118724 @@ End of Day Wrap Sat 17/1/15 Sydney, Australia Time 7:20pm
Hi all,
Great answer today from Heureka, Alan, geno3141, Mathematician, CPhill, flflvm97 and Tetration. Thank you.
Here is a suggestion that may help some people keep a track of the threads that they want to follow.
http://web2.0calc.com/questions/a-suggestion-for-casual-answerers
I also rearranged the puzzles today so they are all in one sticky topic. 
Interest posts:
1) End you day with a laugh. Thank you Rosala, we always love your laughs
http://web2.0calc.com/questions/end-your-day-with-a-laugh
2) Fun with numbers - Suitable for everyone Thanks Chris.
3) Log of complex number. All too much for me. Thanks Alan and Heureka.
http://web2.0calc.com/questions/ln-10-75-6-98i#r3
4) What is a geometric mean. Thanks Geno
http://web2.0calc.com/questions/what-is-geometric-mean_1
5) Using a table of values with Desmos graphing calculator. Thanks CPhill
6) A look at some Trig Thanks to CPhill and Melody
7) Chris and I having a laugh.
http://web2.0calc.com/questions/how-do-you-write-an-equation-for-5-4-and-4-3
Enjoy your weekend
♫♪ ♪ ♫ ♬ ♬ MELODY ♬ ♬ ♫♪ ♪ ♫
+118724 Please take a look at this unit of work.
http://www.mathsisfun.com/geometry/unit-circle.html
I do not like their explanation of tan much but their explanation of sine and cosine looks really good.
Try and understand the interactive pics properly.
Basically if you draw a unit circle (a circle of radius 1 unit) centred at (0,0) then
$$\\sin\theta = y \;value\\
cos\theta = x \;value\\
tan\theta= \frac{y}{x}=\frac{sin\theta}{cos\theta}$$
The (x,y) value that I am referring to is where the arm of the angle cuts the diametre of the unit circle.
The diagrams in the unit are trying to show you why this is so.
The more you understand the less you have to memorise and the easier it is to move on to the next step.
Actually it seems the unit circle is really useful for this question and others I had...yes there were quite a lot more.Thanks guys
