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## #1 Help Me ! » Inverse » 2009-10-24 12:32:05

Kurtz
Replies: 1

Let f(x)= x^3 + 2x + 1, and assume that f^-1 exists and has domain (-∞,∞). Simplify each expression.

f[f^-1(4)]

Do I have to find the inverse and how? because I don't know how else to solve it. thanks

## #2 Help Me ! » Quadratics » 2009-10-11 05:11:37

Kurtz
Replies: 2

1. I do not know how to find the equation using the given, x intercept -6 and y intercept √2..

2. P = -t^2 + 26t +106 where 1 ≤ x ≤ 13
After approx. how many days will 250 people have caught the flu?

Do I just plug in days to find out the approx.? or is there a definite computation?

## #3 Help Me ! » Solving Equations » 2009-10-02 15:46:52

Kurtz
Replies: 1

More problems I don't know what steps I must take to find X or Y.

1.   1/y + 1 = 3/y - 1/2y

2. 3/(x-2) = 5/9x

## #4 Re: Help Me ! » Grouping » 2009-10-02 15:37:01

oops thx that makes a lot more sense because I mess up on writing the problem

it was supposed to be a²x + bx - a²z - bz

thx for overlooking that mistake. and thx so much for helping me.

## #5 Re: Help Me ! » Grouping » 2009-10-02 11:53:53

Or does it become

(x - z) (a^4 - b²)  ?

## #6 Help Me ! » Grouping » 2009-10-02 11:50:29

Kurtz
Replies: 6

Is it possible to solve this problem with the grouping method? It ask to use the grouping method on this to simplify but I think it is not possible.

a²x + bx - a²z - bx

## #7 Help Me ! » Confused with simplifying » 2009-10-01 18:44:59

Kurtz
Replies: 1

How do I simplify this problem....?

x(3-x) - x²(x+1)
________________
2x-2

## #8 Help Me ! » Integer Exponents » 2009-09-28 06:52:02

Kurtz
Replies: 1

How do I simplify this expression? Assuming that letters p and q represents natural numbers.

(2^p-q)(2^q-p+1)

## #9 Help Me ! » Calculus: Derivatives » 2009-01-28 08:53:55

Kurtz
Replies: 1

Hi how do I find the derivatives of:

y= X^X

and

y=X^X^X

My teacher say it is involves implicit solving and natural log "ln"

## #10 Re: Help Me ! » I am useless at proving inequalities » 2008-08-12 19:54:42

Moose that thinking process has been done. I believe I post it above but also another thing is that (A)(B)(C) can not all equal 1 and like Identity showed me is that we must use invert substitution that will also give us the result of one. Not just 1*1*1.

## #11 Re: Help Me ! » Need Help!!! » 2008-08-11 10:04:41

by using the variable "h" you are referring to {\delta} right?

## #12 Re: Help Me ! » Need Help!!! » 2008-08-10 16:50:07

Have you check the "hidden text" given by Daniel and Maths up on top it should help you its done step by step using the limit formula. Just click on it and study it but then it wont help on all of the problems.

So I have one question how would I solve something such as

f(x)= -x² - x + 1    and f(x)= √ x

## #13 Re: Help Me ! » Need Help!!! » 2008-08-09 06:38:26

So we're practically subtracting "f" by one time so like

f(x)= X^2 + 14
will end up with
lim x      because everything else would be cancelled right?

## #14 Re: Help Me ! » I am useless at proving inequalities » 2008-08-08 15:20:01

So what if A*B*C=1 then wouldnt it also all be 1?
because A times B times C = 1 which could be substituted as A=1 B=1 C=1

which is A(1)*B(1)*C(1)=1

Then we're proving the equation false?

## #15 Re: Help Me ! » I am useless at proving inequalities » 2008-08-08 14:03:58

I hope I'm not spamming because I have alot to learn still....

But anyways have you tried

if abc= 1 then   1 + 3     ≥     6
___        ____
Variable    Double Variable

I'm thinking that A+B+C = 1:D plz dont get mad if it seems off the wall.
and it may go the same with the other one but with two abc variable but mixed up which adds to 2, so it might look like this.....

1+ 3  ≥   6
---     ---    =    4  ≥  6
1       2           ---   ---  =   4 ≥ 3              to me it seems to prove the problem hope i helped
1     2

## #16 Re: Help Me ! » Need Help!!! » 2008-08-08 13:51:52

Unfortunately yes it is thats why I'm pretty confused because this how its asked.

Limits and Funtions

For each function, find       lim     f(x+Δx)-f(x)
Δx->0    --------------
Δx

1. f(x)= -3x + 2

2. f(x)= x^2

and so on.....

## #17 Help Me ! » Need Help!!! » 2008-08-08 09:32:31

Kurtz
Replies: 14

How do I find the Limit for a function F(x)= -3x +2

Book studying isn't going too well

## #18 Help Me ! » First Law of Thermodynamics » 2007-11-29 15:41:08

Kurtz
Replies: 1

A 150 kg steel rod in a building under construction supports a load of 6050 kg. During the day, the rod's temperature increases from 22 degree celsius to 47 degree celsius. This temperature increase causes the rod to thermally expand and raise the laod 5.5 mm.

a. Find the energy transferred as heat to or from the rod.(Hint: Assume the specific heat capacity of steel is the same as for iron.)

b. Find the work done in this process. Is work done on or by the rod?

c. How great if the change in the rod's internal energy? Does the rod's internal energy increase or decrease?

## #19 Help Me ! » Conservation of Energy » 2007-11-15 13:36:25

Kurtz
Replies: 1

A worker drives a .500kg spike into a rail tie with a 2.50kg sledgehammer. The hammer hits the spike with a speed of 65.0 m/s. If one-third of the hammer's kenetic energy is converted to the internal energy of the hammer and spike, how much does the total internal energy increase?:/

## #21 Help Me ! » Momentum » 2007-10-22 12:39:23

Kurtz
Replies: 2

A moving object has a kinetic energy of 150 J and a momentum with a magnitude with a magnitude with a magnitude of 30.0 kg m/s. Determine the mass and speed of the object.

thanks.

## #23 Help Me ! » Conservation of Momentum » 2007-10-18 12:05:24

Kurtz
Replies: 2

Each croquet ball in a set has a mass of .50 kg. The green ball, traveling at 12.0 m/s, strikes the blue ball, which is at rest. Assuming that the balls slide on frictionless surface and all collisions are head-on, find the final speed of the blue ball in each of the following situations:

a. The green ball continues moving after the collision at 2.4 m/s in the same direction.

## #24 Help Me ! » Physics: Power » 2007-10-11 13:04:41

Kurtz
Replies: 1

I don't get how how to find the power? Do we use P=Fv?

Water flows over a section of Niagara Falls at the rate of 1.2 x 10^6 kg/s and falls 50.0m. How much power is generated by the falling water?

and also...

How long does it take a 19kW steam engine to do 6.8 x 10^7 J of work?

## #25 Re: Help Me ! » Conversion » 2007-10-03 13:52:36

What should I use to solve this problem?

A boat moves through the water with two forces acting on it. One is a 2.10 x 10^3 N forward push by the motor, and the other is a 1.80 x 10^3 N resistive force die to the water.
a.If it starts from rest, how far will it move in 12 s?
b.What will its speed be at the end of this time interval?