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## #1 Re: Dark Discussions at Cafe Infinity » Global Warming- It's Happening! » 2008-08-16 14:43:26

yes it was a great movie to open peoples minds to what's going on in the world. People who are interested in this subject should check out Project Earth on the discovery channel. It is focused on ideas to help solve this issue, one of the proposals is launching a bunch of mirrors into space to reflect the suns heat away from the earth.

## #2 Re: This is Cool » 0.9999....(recurring) = 1? » 2008-08-15 16:22:15

Wow this is a crazy concept to grasp...

## #3 Re: Help Me ! » Need Help with Area » 2008-08-15 16:14:24

Hey thanks a lot! Thant really helped.

## #5 Re: This is Cool » 0.9999....(recurring) = 1? » 2008-08-13 07:52:46

Hmm yeah... I guess I was thinking about the problems where you have to determine if an equation is true such as 2x-1=2, x=1 which would be false... I am just wondering how 0.999... can be equal to 1 if they are not the same, because in theory 0.999... would get infinitely closer to 1 but would never actually reach 1. Such as in Physics when someone touches someone else, in theory we are really never touching them because the atoms electron clouds would prevent the nucleui from thouching each other, but we do get an electrical signal to the brain signifying touch... Another example is when an oblect moves halfway to another object then halfway again, then halfway again to infintity but the object can in theory always move another half closer to the other object... 0.25(0.5)=0.125; 0.125(0.5)=0.0625 then it would move on to infinity... I guess in theory 0.999... is not equal to 1, but in reality we set it equal to 1 to make computing easier, just like in theory we never actually touch each other but in reality we feel as if we do because of what our brain is telling us...

## #6 Re: Coder's Corner » Math puzzle? » 2008-08-12 12:06:05

wow that's interesting! I, or rather my teacher found a geocache near my house when we were looking for snakes: I think I wanna put one somewhere...

## #7 Re: Coder's Corner » MNEMONICS. » 2008-08-12 11:50:57

PEMDAS. Please excuse my dear aunt sally.

## #8 Re: Dark Discussions at Cafe Infinity » Global Warming- It's Happening! » 2008-08-12 09:50:51

Al Gore's movie is called An Inconvienent Truth...

Also global warming is happening slowly with an average temperature increase of less than 1 degrees F. We will most likely not see an ice age and our future kids will probably not either. As for Iron dust, I think that would kill some species of fish throwing the food chain out of whack, plus humans have harmed the oceans enough aleady. As for turning off computers and electronics, you may still have 'ghost' electricity running through the wires. The only way is to disconnect the electronics, which is a huge hassle. Just continue living your life and recylce when able. Life has survived future ice ages and I think humans can as a whole make it through this one with all of the technology and new knowledge we have available to us.

## #9 Re: Dark Discussions at Cafe Infinity » Global Warming- It's Happening! » 2008-08-12 09:20:02

JaneFairfax wrote:

A friend of mine has written a sonnet about Global Warming:

http://z8.invisionfree.com/DYK/index.php?showtopic=4

I thought it was a very good poem.

Wow that was great!

## #10 Re: This is Cool » 0.9999....(recurring) = 1? » 2008-08-12 09:07:23

hmm this is a vey interesting subject, indead!

As Ricky said if you have 1/3=0.333...  & you multiply both sides by 3 then you would get 1=0.999...  But then doesn't that make it true that 1 is not equal to 0.999...  ?  Wow amazing how great the span of math is, it is similar to space, how we cannot grasp it being Infinite

## #11 Re: This is Cool » end of world » 2008-08-12 08:45:32

haha crazy stuff...

## #12 Re: Help Me ! » I am useless at proving inequalities » 2008-08-12 08:32:28

oh I though a,b,c were = 1 so that:

1+3/((1)+(1)+(1)) 1+6/((1*1)+(1*1)+(1*1))

1+1=2 1+2=3.  Oh but then 2 is not equal to 3

Hmm... So who figured it out?

## #13 Re: Help Me ! » Algebra (lol) » 2008-08-12 08:17:26

ah no cookie, oh but a cake! Yay! Smashs face in cake:..

## #14 Re: Help Me ! » Need Help with Slopes » 2008-08-12 08:06:29

hmm that's what I figured. That's what physics taught me with delta LOL.  Thanks again!

## #15 Help Me ! » Need Help with Area » 2008-08-11 17:49:55

MooseofDoom
Replies: 3

If anyone can help it would be great!

AREAS

For the following functions, you will estimate the area underneath the curves between x=1 and x=3. You will be using rectangles to help you estimate this area.

Each rectangle you use in your estimation will have equal widths. The number of rectangles use will be given. EX. USING 8 RECTANGLES IN THE INTERVAL FROM X=1 TO X=5 WILL RESULT IN THE WIDTHS BEING 0.5 IN LENGTH. The base of each rectangle will be the x-axis and the upper left corner of the rectangle will make contact with the curve. The upper right corner will either be above or below the curve. The left had will determine the height.

Procedure for estimating an area. Function: y=2x+1 from x=1 to x=3 using 4 rectangles. Widths of each rectangle will be 0.5. Height of the first rectangle is determined by using x=1. Height of second rectangle is determined by using x=1.5. Height of the third rectangle is determined by using x=2. And the height of the fourth rectangle is determined by using x=2.5. Add all the areas of each rectangle to get estimation. Notice that this estimation is an underestimate based on all rectangles being drawn below curve, leaving some "empty space" not accounted for.

Find the approximate areas for each function from x=1 to x=3 using 8 rectangles of equal width.
1. y=-x²+4x
2. y=x²-4x+5
.
.
.
7. Approximate the area of the following semicricle y= √ -x²+6x. Use 12 rectangles of equal width. Then, find actual area of semicircle and compare with the estimation.

So what i figured out is that for #1 each rectangle will have a width of 0.25. Then do I plug in the x into y=-x²+4x? Like y=-(1)²+4(1) which would give me y=3. Then I multiply 0.25(3) and get 0.75 for the area of the first rectangle out of 8.... so then just add all of the rectangles together?

Let me know if I am doing it right... I don't know how to do #7 so if someone could explain that would be great!

## #16 Re: Help Me ! » Need Help with Slopes » 2008-08-11 16:20:20

Hmm... Wow thank you so much I think I get it now! Thanks again! For x=-2 is the change from x=-2 to x=-1 equal to 1 or -1? A change in rate can only be positive right?

Woah...

## #18 Re: Help Me ! » Algebra (lol) » 2008-08-11 08:19:32

Locus? is that suppose to mean focus? CoNfUsEd!

## #19 Re: Dark Discussions at Cafe Infinity » Batman The Dark Knight » 2008-08-11 08:11:22

It was amazing! Heath Ledger scared the bahgebers outta me... Insane movie, the best Batman yet... Plus Alfred the butler is always great!

## #20 Help Me ! » Need Help with Slopes » 2008-08-11 07:03:50

MooseofDoom
Replies: 4

I was wondering if anyone knows what to do for the following math problems for my AP Calculus class:

For the following functions, you will find the average rate of change over the specified intervals and use the results to estimate the instantaneous rate of change at a point.

Find the rates of change:
A)  Between x=1 and x=2, x=1 and x=1.5, x=1 and x=1.23, x=1 and x=1.1, and x=1 and x=1.05. Use this to estimate the instantaneous rate of change at x=1.
B)  Between x=-2 and x=-1, x=-2 and x=-1.5, x=-2 and x=-1.75, x=-2 and x=-1.9, and x=-2 and x=-1.95. Use this to estimate the instantaneous rate of change at x=-2

Then the first problem on the W/S is as follows:

Functions
1. y=-x²+4x

Can anyone explain to me how to solve this?

Thanks
~MooseofDoom

## #21 Re: Help Me ! » Need Help!!! » 2008-08-10 17:22:30

Doh... Yeah clicking on Hidden Text helps a lot lol.... Thanks

## #22 Re: Help Me ! » Need Help!!! » 2008-08-10 16:44:00

Hey Kurtz, how do you do it?