Homework Help Thread

[Eminem4Life1006]

Any tips on how to improve in Calculus/better understand it? I am completely lost now..it's so fast paced I can't grasp it that easily..any tips would be helpful .

[mrjizzbomber]

Any tips on how to improve in Calculus/better understand it? I am completely lost now..it's so fast paced I can't grasp it that easily..any tips would be helpful .

Do you understand algebra? Thats the first step.

Do you understand the concept of limits? Thats the second step.

Without a full grasp of algebra and limits, you're going to struggle with calculus. If you understand both of those, this is how you take the leap:

Taking the derivative of a function means converting your function to a different function. Your original function tells you the location (in y) of every point (in x). For example:

y = 2x

This tells you that for every point (x), the value (y) is twice x. If x is 3, y is 6. if x is 5, y is 10.

Now, the converted function will tell you the slope (in y', read y prime) of every point (in x). Eventually you will learn shortcuts to do the conversion from the original function (y) to the slope function (y prime). I can easily look at the equation and tell you that the slope function is:

y' = 2

This means that at every point the slope is 2. Since x isn't in the y' equation, the slope is independent of y. Heres another example... Original equation:

y = x^2 (x squared)

Converting this function to the slope function (more commonly you would say: taking the derivative of y) will result in:

y' = 2x

OK, this tells you that for every point (x) the slope is 2 times x. At x = 2, the slope is 4. At x = 0, the slope is 0. At x = -4, the slope is -8.

Now the important part. To take those two derivatives I used 'shortcuts', but that doesn't really tell you where the concept came from. That comes from something called the 'limit definition of a derivative'. I will give you a brief overview of that derivative, then give you some links with graphical descriptions.

As I said before, the original function tells you the position (in y) for every point (x). The derivative changes this to a slope function, telling you the slope (in y') for every point (x). From algebra, you know that slope is defined as rise over run (change in y divided by change in x). Another way to write that is:

(y2 - y1) / (x2 - X1)

This equation gives you the slope for a line. It is only correct for a line, or it will result in the 'average slope' between the points x1 and x2. To find the slope of something non-linear, you need to find the 'point slope'. Point slope just means the slope at a point, and a point is just an infinitely small line segment. To find the point slope you need to use the equation above (y2-y1/x2-x1), where the line segment (x2-x1) approaches zero. Basically, you are taking using the concept of limits to change your 'line segment slope' equation into a 'point slope equation'. This is the most important, and difficult, step to understanding calculus (at least to understand derivatives), so make sure you get it (even if it takes some time).

Heres something that will explain it using graphs and pictures:

http://en.wikipedia.org/wiki/Derivative
Definition via difference quotients (read this section / the section before)

http://tutorial.math.lamar.edu/Classes/ ... ative.aspx
(Note: These notes are GREAT for all higher levels of math)

I am assuming you are only doing derivatives right now. Eventually you will get to integrals, which is basically the anti-function to the derivative. Integrals will tell you the area under the curve, from one point (x) to a second (x). Integrals and derivatives are related by the fundamental theorem of calculus. After understanding the limit definition of a derivative, the fundamental theorem of calculus is the next big topic to grasp.

After you fully understand derivatives and integrals, you will basically spend calculus learning ways to apply them to word problems. It is very similar to algebra, you only really learn a handful of mathematical concepts, but spend a year learning how to apply those concepts (techniques, strategies, etc.) If you understand algebra, and get a hang of derivatives and integrals, it will all become a lot easier as you go on.

- The Bomber

[mrjizzbomber]

Also note, when these websites write the slope equation, they wont write y2-y1/x2-x1

You'll see something like f(x) - f(a) / (x-a)

And then they take the limit as x-->a

Its OK. Its the same thing

- The Bomber

[FAME]

I need to find a topic for a history paper. Basically I want to do something during the Enlightenment period (1600s to 1800s), links would be great on maybe timelines or anything else, so I can pick a topic. THANKS

[Dazed]

I need some urgent math help guys..

Carmel (girls name) put $5000 into 3 different accounts paid interest of 8%, 10%, & 7%. Total interest at the end was $405. If carmel invested $500 more at 10% then at 8% find amount invested in each,


2.

A package of shapes contains squares, pentagons, and hexagons. there are 24 shapes in the package with a total of 112 sides. If there are 10 more squares than pentagons, find # of of each shape.

3.

During the day a truck driver encounters light ,moderate, & heavy traffic. If he travels 1/3 hour in light, 1/2 hour in moderate, and 1/5 hour in heavy he can cover 21 miles. If he travels 1/5 in light, 1/4 in moderate, and 1 hr in heavy he can cover 16 mi. The sum of his speeds in moderate & heavy is 5 mi less than his speed in light. Find his speed in each type of traffic.


Use 3 variable system to solve.


So i can show work, or just give me the answer if you have your own way and not the system way.

I would really appreciate it.

[Dazed]

Thats not Stats though?

[Dazed]

Nah, its systems of equations just using 3 variables is the way to solve them.

[gutawafang]

2.

A package of shapes contains squares, pentagons, and hexagons. there are 24 shapes in the package with a total of 112 sides. If there are 10 more squares than pentagons, find # of of each shape.

Square-4 sides
Pentagons-5 sides
Hexagons-6 sides

See, just minus away using sides.

First, take out all the extra 10 squares so that the number of squares=the number of pentagons.
So, 112-(10)(4)=82

So, after taking away 10 squares, there's 14 shapes left.

Now slowly, or by using this method I call Trial and Error,

5 square=20 sides
5 pent=25 sides
4 hex=24
Total=69

4 square=16
4 pent=20
6 hex=36
total=72

3 square=12
3 pent=15
8 hex=48
total=75

2 square=8
2 pent=10
10 hex=60
total=78

1 square=4
1 pent=5
12 hex=72
total=81

You continue, can? I donno why I don't get 82 sides. I got 81. Or maybe I'm wrong.

EDIT: I made a careless mistake. I'm so sorry.

So, 112-(10)(4)=72

this is the answer!
4 square=16
4 pent=20
6 hex=36
total=72

So, add back the ten squares.

Final answer-
14 sqaures
4 pentagons
6 hexagons

[Dazed]

thanks, can you help me with the otehr 2?

[gutawafang]

thanks, can you help me with the otehr 2?

If you need it quickly, I don't think so. LOL. I'm currently very very busy doing my school assignments.

I have to turn a 2d image into 3d using Maxon Cinema 4d.

But if I'm free later, maybe I will. But the rest looks hard.

No promises.

[Dazed]

thanks, can you help me with the otehr 2?

If you need it quickly, I don't think so. LOL. I'm currently very very busy doing my school assignments.

I have to turn a 2d image into 3d using Maxon Cinema 4d.

But if I'm free later, maybe I will. But the rest looks hard.

No promises.

Oh well if you don't have time it's fine.

I need it by 6 am tomorrow, which is 11 hours from now so..

[gutawafang]

Carmel (girls name) put $5000 into 3 different accounts paid interest of 8%, 10%, & 7%. Total interest at the end was $405. If carmel invested $500 more at 10% THAN at 8%, find amount invested in each,

First, find out Carmel's last name. Lol jk.

Ok, the more times i read this shit, the harder it becomes.

You see, he got 5k rite?

Then there's 3 bank accounts. It's just weird why he wanna invest in diff accounts in the first place. He should just invest all in the highest interest one. Fuck this guy. LOL.

Ok, with his 5k, he invested in 3 places. BUT we don't know the AMOUNT he put in each. And we know the TOTAL interest he gets at the end, which is 405 bucks.

Fuck all that now.

We'll do this shit the same way we did for just now question.

I think you got the idea.

......

First, we minus off 500 dollars so that

the amount he invested in 10% and 8% is equal.

so he invested 4500 total.

And his interest is (10/100)(500) less. So his interest in the end is 405-50=$355.

$355.

Fuck this, I'll just algebra this shit. I wont be sure. I'll just try.

x=the interest he get from 8 and 10 percent banks
y=the interest he get from the 7 percent bank

2x+y=355
y=355-2x

Fuck, this is the farthest I can go.

[Dazed]

Actually thats supposed to be used with algebra, the way you set it up but using three variables, i just dont know how -.-

[gutawafang]

Alright algebra.

Carmel (girls name) put $5000 into 3 different accounts paid interest of 8%, 10%, & 7%. Total interest at the end was $405. If carmel invested $500 more at 10% THAN at 8%, find amount invested in each,

He invested x in both 10 and 8. And y in 7.

5000-500 to equalize two of the 10 and 8.

So, 2x+y=4500.

2x+y-4500=0

solve that. ?

[gutawafang]

Guta you're stereotype is being confirmed with every post bro

What do you mean?