#392**+8 **

@@ End of Day Wrap Mon 5 /1/15 Sydney, Australia Time 10:30pm ♪ ♫

Hi everyone,

I have not posted a wrap for a few days. I have been preoccupied I am sorry.

There have been many great questions and most of these were answered very well by Tetration, CPhill, ororen1909, NotTheBestMathMaster, rajaae, Kitty<3, Alan, and geno3141. Thanks all

Now there were many good post. Here are some of them.

Every maths mover must be able to find something interesting in there.

1) Interesting domain question.

http://web2.0calc.com/questions/what-is-the-domain-of-this-function-sqrt-x-3-x-2#rr1

2) Interesting trig. Unit circle and exact values. Melody

3) What are permutations and combinations ? Melody

http://web2.0calc.com/questions/how-many-possible-combinations-are-there-for-a-deck-of-cards

4) A really good rates and volume question. Melody

http://web2.0calc.com/questions/help-with-problem_1#rr5

5) Physics Thanks Alan

6) Some geometry. Chris would like someone to check his answer but he thinks it is good. Thanks Chris.

7) All in fun :)) NotTheBestMathMaster, Melody, Nauseated, Alan and CPhil.

8) Formula for triangular numbers Thanks Alan and Chris

9) Parabola question, different from the norm - Thanks Alan

10) This is not a high level question but I liked it. (percantages) :)

11) A couple of revision/learning sites suggested by Chris

12) Proof by Induction Thanks Chris

http://web2.0calc.com/questions/math-induction

That is it for today. Thanks everyone

♫♪ ♪ ♫ ♬ ♬ MELODY ♬ ♬ ♫♪ ♪ ♫

MelodyJan 5, 2015

#203**0 **

Tues 6/1/15

1) This is an old one but many people have been away on holidays and I'd really like people to read my new years message. It is just intended as a thank you to you all.

This is the wrap address but it links to mine and Rosala's new year messages. :)

http://web2.0calc.com/questions/all-questions-answered-to-this-point#r390

2) I am still thinking about this area question

3 ) Imaginary numbers $$\sqrt[4]{-1}$$ I liked this one.

http://web2.0calc.com/questions/square-root-of-i

♫♪ ♪ ♫ ♬ ♬ MELODY ♬ ♬ ♫♪ ♪ ♫

MelodyJan 5, 2015

#1**+5 **

Answering some of those questions you posted yesterday sent me scurrying back to refresh my memory too, JayyH !!!!

But that's OK........it's always good to review things.....

Here's a couple that I used.....

http://www.mathwarehouse.com/geometry/

If it's any consolation...I always found this topic a little difficult, as well!!!

CPhillJan 5, 2015

#1**+5 **

y=-x^3+x^2-2.....the tangent line will be horizontal wherever the derivative = 0

So, the derivative is given by

y ' = -3x^2 + 2x

Set this to 0...so we have.....

-3x^2 + 2x = 0 factor

x(-3x+ 2 ) = 0 set each factor to 0

x = 0 and x = 2/3

Here's the graph showing the points of interest......https://www.desmos.com/calculator/aewacr9y2d

CPhillJan 5, 2015