## Why does the calculator number start from 0 at the bottom and go up, while telephone numbers go down from 1?

i really want to know

It is pretty odd that a calculator and a touch-tone telephone have exactly opposite layouts for their keypads, which have many identical components. The reasons behind the differences are not known for certain, but a few theories exist.

One theory refers to a study done by Bell Labs in 1960. This study involved testing several different telephone-keypad layouts to find out which was easiest to master. After testing several layouts, including one that used two rows with five numbers each and another that used a circular positioning, it was determined that the three-by-three matrix that had 1, 2 and 3 across the top was the easiest for people to use.

Another theory is based on the layout of a rotary telephone. On a rotary dial, 1 is at the top right and zero is on the bottom. When designing the new touch-tone keypad, putting the 1 on the top-right didn’t make much sense, because Western writing is read from left to right. But putting 1 on the top-left, and the subsequent numbers to the right, did make sense. Using that formula, the resulting rows fell into place, with zero getting its own row at the bottom.

All of these theories attempt to explain why telephone and calculator keypads are exact opposites, yet no one theory can be pinpointed as the definitive reason. It is common practice today to use the telephone-keypad layout when designing new products that utilize a keypad, such as Automated Teller Machines.

If you want to read the other theories, click on the link.

## is (cosx)/(x) even, odd, or neither?

I think its odd b/c even though cos x is an even function, dividing it by negative x makes the whole thing negative—or does the negative x in the denominator only apply partially, in which case it would be neither…I hope the question made sense
and btw–how do I find the domain and range w/out a graph? I never know which is which.

F is even if f(-x) = f(x) and odd if f(-x) = -f(x)

For cos(x) / x

cos(-x) / -x = cos(x) / -x = -cos(x) / x = -f(x) (since cos(x) is an even function).

Therefore it is odd.

/////////////////////////////////////////////

Another way to think about this is that the numerator cos(x) is an even function and the denominator is an odd function, therefore the result is odd, since the quotient of an even and odd function is odd.

If you graph cos(x)/x then you will see that the graph is symmetric with respect to the origin.

EDIT:

Remember: domain is which x values can work for this function. The range is which y values can this function PRODUCE.

For this particular function, since you are dividing by x, then you have to restrict x from being zero. So zero, cannot work, so we must throw it out.

Therefore, the domain is (-inf, 0) U (0, +inf).

For the range, it is difficult to figure out without the calculator, it turns out to be all real values, (-inf, +inf).

## Ok, which bra calculator should I use?

I have punched my measurements into several calculators for bra sizing and have been given ALL DIFFERENT SIZES. Each calculator gave me different sizes for the same measurements. WTF. Yes, these were all US. measurements and yes, I still got all different sizes.

A lot of calculators use this old formula that adds 4-5 inches to your band measurement. That’s outdated — that was developed back before bras had good elastic.

Also if you’re an odd number or a half inch on either measurement, calculators will round up and down, which will give you different measurements.

Use this guide: http://beyondjane.com/fashion/style/how-to-find-the-right-bra-and-how-to-make-it-last/ and do the calculation yourself.

## Is a voice activated calculator a good idea ?

No, in my opinion a voice activated calculator is not a good idea.

The precision will be poor, and you’ll likely have to introduce something like Polish notation to make it practical – and most people don’t understand Polish notation. Inserting equations will be difficult at any rate. Also, if you need a calculator, odds are the people around you also need calculators – and you’ll be disturbing them with your voice activated calculator.

## Maths Calculator Exam Today.. Edexcel!?

How did people find it?
can you remember any of the answers to the questions?

What is the percentage to get a B?

I found it allright – some difficult things though towards the end
GCSE – Year11 btw
GCSE – Year11 btw

I had the same exam today ..found it ok , there were the odd few questoins but aslong you got the rest right! Youll get an A!

Marks depend on the nations results. In a practice paper i got 55out of 90 and it was an A . National restults for that year.

So il predict about 40-60 but then again you probably done better ! Aim high bro!