# Mathematics

### #1

Posted 11 February 2010 - 01:30 PM

So, on Monday in Calc 3, we did this really fun integral.

1 x

/ /

| | dy dx

/ /

0 x^2

That's the best I can do at rendering it into this. >_>; Anybody wanna take a crack at it? :>

Kingroy: ( 4:40 PM - 02/10/14) u can't own black people

Kingroy: ( 4:40 PM - 02/10/14) #ThanksLincoln

### #2

Posted 11 February 2010 - 01:36 PM

But I did bad, I wasn't prepared and I was sick too. I think I failed.....

But not with the total average I got, I think I will pass but there is the chance I fail.

So, I am in the finals. I finished physics, was easy but hell lot of questions. u2sinO/2g baby!(O is theta).

I am still in 3rd LV (that's 11th std)

Calculus? Still haven't met it.

### #3

Posted 11 February 2010 - 01:43 PM

Fail. Calculus is quite possibly the most enjoyable class you can possibly take in any school ever. It's mostly fun because it's so easy.Calculus? Still haven't met it.

YES, I SAID IT. Calculus is easy. It's the Algebra and Trigonometry that gets all muddled up in the Calculus that makes it "hard" for some people. Integrals and Derivatives are eeeeeasy shiz. <3

Also~ Coolest Math fact OF ALL TIME.

iπ

e + 1 = 0

Why is it so pretty? It uses addition, multiplication, and exponentiation exactly once each along with incorporating the important constants 1, 0, e, i, and π all into one, tiny little equation. <3

Kingroy: ( 4:40 PM - 02/10/14) u can't own black people

Kingroy: ( 4:40 PM - 02/10/14) #ThanksLincoln

### #6

Posted 11 February 2010 - 02:01 PM

A bag is know to contain a marble that is either red or green.

A green marble is added to the bag.

The bag is shaken, and a marble is removed. It is green.

The marble is replaced, the bag is shaken, and another marble is removed. It is green.

What is the probability that the remaining marble is red?

### #7

Posted 11 February 2010 - 02:02 PM

Calc is easy. Pre-Calc is a bitch. In Pre-Calc you need to know a shit-ton of obscure Trig formulas and identities along with lots of algebra tricks on top of learning the basics of WHY Derivatives and Integrals do what they do.Oh man, you saying Calculus is easy makes me feel like a failure for working my butt off in Pre-Calc just to have a low B. It's easily my worst subject.

It's a pain until you get past the initial Limits. Once you start doing Derivatives and Integrals with shortcuts, the Trig and Algebra is the only difficult part. I still suck at Trig, so don't worry. >__>;

Who ever remembers that cos2x = cos²x - sin²x ? I didn't until my Professor brought it up lol.

Also~ Probability problems... D:

I think 25%. Since there are 2 Marbles. The first one is Red or Green. The second is definitely Green. (50% + 0%)/2 = 25% :>

Kingroy: ( 4:40 PM - 02/10/14) u can't own black people

Kingroy: ( 4:40 PM - 02/10/14) #ThanksLincoln

### #8

Posted 11 February 2010 - 02:05 PM

A bag is know to contain a marble that is either red or green.

A green marble is added to the bag.

The bag is shaken, and a marble is removed. It is green.

The marble is replaced, the bag is shaken, and another marble is removed. It is green.

What is the probability that the remaining marble is red?

Wow! And I thought Probability is the easiest thing around.

EDIT:

Percentage?

I never got there.

Except where they ask me about 52 cards and 4 removed what is the probabilty a card a daimond and other stuff.

Also mixed with Permutation and Comabination.

48C4 something like that.

Also Die and Coin and those thing.

**Edited by Deadly-Dreamer-X, 11 February 2010 - 02:08 PM.**

### #9

Posted 11 February 2010 - 02:07 PM

Probability and statistics are easily my strong suit with math. I'm opting out of AP Calc next year for the AP Stat solely because I doubt I will go into a profession that will require calculus. And I'll do much better in Stat

### #10

Posted 11 February 2010 - 02:11 PM

Yeah, those trig formulas were just so pointless that I just couldn't remember it at all.

Probability and statistics are easily my strong suit with math. I'm opting out of AP Calc next year for the AP Stat solely because I doubt I will go into a profession that will require calculus. And I'll do much better in Stat

Economics? Cause they also need high amount of Statistics there.

Arithematic Progression? Did you guys ever seen Geometric progression?

I need calculus, I learned some derivation using Calculus.

Trig is my fav.

sinx-siny = - 2 cos x+y/2 sin x-y/2

### #11

Posted 11 February 2010 - 02:27 PM

"Censorship is telling a man he can't have a steak just because a baby can't chew it."

— Mark Twain

“I divide my officers into four classes; the clever, the lazy, the industrious, and the stupid. Each officer possesses at least two of these qualities. Those who are clever and industrious are fitted for the highest staff appointments. Use can be made of those who are stupid and lazy. The man who is clever and lazy however is for the very highest command; he has the temperament and nerves to deal with all situations. But whoever is stupid and industrious is a menace and must be removed immediately!”

— General Kurt von Hammerstein-Equord

### #12

Posted 11 February 2010 - 02:30 PM

G

_{1}G

_{2}

G

_{1}G

_{1}

G

_{1}G

_{2}

G

_{2}G

_{1}

G

_{2}G

_{2}

and

R

_{1}G

_{1}

R

_{1}R

_{1}

R

_{1}G

_{1}

G

_{1}R

_{1}

G

_{1}G

_{1}

G

_{1}G

_{2}

G

_{1}G

_{1}

G

_{1}G

_{2}

G

_{2}G

_{1}

G

_{2}G

_{2}

and

R

_{1}G

_{1}

_{1}R

_{1}

_{1}G

_{1}

_{1}R

_{1}

G

_{1}G

_{1}

### #13

Posted 11 February 2010 - 02:39 PM

That makes sense, I suppose. >.>Then it's just wanted/total, so 1/5, or 20%. I think. >___>:

HMMMM. What about this probability problem?

Jeffrey the Squirrel throws five acorns from his tree, trying to hit Albert the Squirrel in the neighboring tree. He's a pretty good shot and judges his chances to hit from where he is, given wind speeds and other such things that Squirrels don't actually know about, are thirty-five percent. What are the odds that Jeffrey will hit Albert with at least three of the acorns, assuming Albert does not move when hit?

Kingroy: ( 4:40 PM - 02/10/14) u can't own black people

Kingroy: ( 4:40 PM - 02/10/14) #ThanksLincoln

### #14

Posted 17 February 2010 - 09:52 PM

That makes sense, I suppose. >.>

HMMMM. What about this probability problem?

Jeffrey the Squirrel throws five acorns from his tree, trying to hit Albert the Squirrel in the neighboring tree. He's a pretty good shot and judges his chances to hit from where he is, given wind speeds and other such things that Squirrels don't actually know about, are thirty-five percent. What are the odds that Jeffrey will hit Albert with at least three of the acorns, assuming Albert does not move when hit?

~18%

*crosses fingers*

**Edited by Artemis, 17 February 2010 - 09:56 PM.**

### #15

Posted 17 February 2010 - 10:06 PM

That makes sense, I suppose. >.>

HMMMM. What about this probability problem?

Jeffrey the Squirrel throws five acorns from his tree, trying to hit Albert the Squirrel in the neighboring tree. He's a pretty good shot and judges his chances to hit from where he is, given wind speeds and other such things that Squirrels don't actually know about, are thirty-five percent. What are the odds that Jeffrey will hit Albert with at least three of the acorns, assuming Albert does not move when hit?

My guess is around 4 percent.

### #16

Posted 17 February 2010 - 11:19 PM

~18%

*crosses fingers*

~23.5%, actually.My guess is around 4 percent.

You need to use the formula:

P =

_{n}C

_{r}x p

^{r}x q

^{n-r}

where n is the amount of shots and r is the amount you want him to make successfully. p is the probability of success while q is the probability of failure (1-p). You have to do this 3 times, for r=3, r=4, and r=5 and subsequently sum up the three probabilities to get the probability of him connecting with AT LEAST three acorns.

Kingroy: ( 4:40 PM - 02/10/14) u can't own black people

Kingroy: ( 4:40 PM - 02/10/14) #ThanksLincoln

### #18

Posted 17 February 2010 - 11:28 PM

~23.5%, actually.

You need to use the formula:

P =_{n}C_{r}x p^{r}x q^{n-r}

where n is the amount of shots and r is the amount you want him to make successfully. p is the probability of success while q is the probability of failure (1-p). You have to do this 3 times, for r=3, r=4, and r=5 and subsequently sum up the three probabilities to get the probability of him connecting with AT LEAST three acorns.

I knew my answer wasn't right because I wasn't expressing the other probabilities of the last two throws or if two of the first three throws missed.

lol wut i did (.35)^3=.04 (about)

1.) 37.32 m

2.) toward the weak one straight on

3.) away from the raptors?

Also. Iggy, is that original integral in post #1 equal to (1/6)?

**Edited by Lexaeus, 18 February 2010 - 12:04 AM.**

### #19

Posted 18 February 2010 - 06:44 PM

Yush.Also. Iggy, is that original integral in post #1 equal to (1/6)?

NEW PROBLEM.

Find the volume contained beneath the graph of

z = 4 - x

^{2}- y

^{2}

in the first octant. (Problem in 3D)

Hint~ You're gonna use the formula:

/ /

| | f(x,y)dA

/ /

.R

Kingroy: ( 4:40 PM - 02/10/14) u can't own black people

Kingroy: ( 4:40 PM - 02/10/14) #ThanksLincoln

### #20

Posted 18 February 2010 - 09:46 PM

Yush.

NEW PROBLEM.

Find the volume contained beneath the graph of

z = 4 - x^{2}- y^{2}

in the first octant. (Problem in 3D)

Hint~ You're gonna use the formula:

/ /

| | f(x,y)dA

/ /

.R

So...this one look took forever x_X

ill scan my work to show these buggers how its done