Melody

Thurs 29/10/15

1)  Fun on the forum         

    http://web2.0calc.com/questions/what-happens-if-i-eat-pi

2)  Great area problem.   Thanks for providing it Alan  

     http://web2.0calc.com/questions/here-s-a-puzzle-for-when-the-site-activity-is-low

3)  Difficult integral.    Thanks Alan

    http://web2.0calc.com/questions/integral-of-1-a-2-b-2-3-2-integrate-over-b#r7

4) Prove a log funtion is odd.    Thanks Rom.   

    http://web2.0calc.com/questions/prove-that-f-x-ln-x-x-2-1-0-5-is-an-odd-function

5) Slight variation on factoring a quadratic.   Thanks Rom.     

    http://web2.0calc.com/questions/factoring-an-equation#r2

6) Making sense of a G.P.    Thanks Heureka    

  http://web2.0calc.com/questions/1-16-246-4096-4294967296

7)    

@@ What is Happening?  [Wrap4]    Tues 27/10/15   Sydney, Australia Time 10:49pm   ♪ ♫

Hello everyone,    

We have had some terrific answers today from Saseflower, Rom, CPhill, Sportzkid28, Heureka, Omi67 and lots of guests.      

If I missed your name I am sorry I do not have the time to do this as thoroughly as I would really like to.       

Interest Posts:

1) Fun with mathematics.     Thanks guest

\(\frac{m}{7} +7\le9\\ \frac{m}{7} \le2\\ m\le 14\)

z(4y-6)>12

What  about it?    You cannot solve it because there are 2 unknowns.   

Thanks Omi,

I didn't know you could do chemistry.  I like your answer :))

Dank Omi,
Ich wusste nicht, man konnte die Chemie zu tun. Ich mag deine Antwort :))

Translation

in a family of three children, considering the birth of a boy and a girl still plausible events veryatnost find that all the boys in the family

What does this mean?

Maybe it means what is the chance of all three children in a family are boys.

0.5*0.5*0.5 =   1/8    or    0.125 = 12.5%

Что это значит?
Может быть, это означает, что вероятность всех трех детей в семье мальчики.

6b-3+7b+5

=6b+7b       -3+5

=    13b         +2

Thank you Shellbie for being so polite.  We appreciate good manners here :))

Thanks guest that is an interesting way to tackle this question.

The Consumer Price Index is reported monthly by the U.S. Bureau of Labor Statistics. It reports the change in prices for a market basket of goods from one period to another. The index for 2000 was 172.2. By 2012, it increased to 229.6. What was the geometric mean annual increase for the period?

I am going to try using the compound interest formula

\(FV=PV(1+r)^n\\ 229.6=172.2(1+r)^{12}\\ 1.333333333333333333333=(1+r)^{12}\\ \mbox{raise both sides to the power of 1/12}\\ 1.333333333333333333333^{1/12}=((1+r)^{12})^{1/12}\\ 1.333333333333333333333^{1/12}=1+r\\ r=1.333333333333333333333^{1/12}-1\\ r=0.024263181\\ r=2.426 \%\;\;\;\;approximately\)

These should  help.