John J

Here is my problem. I'm using Word 2007 on Windows 7. I was working on a paper, saved it, made some changes, then I forced shutdown. When I restarted my computer, I opened the doc file, and there was a message saying something along the lines do I want to revert to what I was doing. I clicked no (because I thought I had saved the paper prior to the shutdown), however I realized that the saved version wasn't the most up to date version of the document. I then went to the recycling bin to restore whatever I had deleted. The problem now is despite restoring the backup message from Word, I still can't find the version of my Word document I had prior to forced shutdown.

I already tried clicking on the file from the folder and choosing restore previous version, however that only had an even earlier version. If anyone could help me it would be greatly appreciated.

I know that for game 6 and 7, they wore the all red ones. Did they wear the dark SL caps and/or the dark (with red brim) ones with the bird logo in any of the games?

Thanks.

Use logarithmic differentiation to find the derivative of the function: y = ( cos (6x) ) ^ x

I tried using Wolfram Alpha which resulted in y' = [( cos (6x) )^ x ] [ log (cos 6x) - 6x tan (6x)] but it was marked wrong.

Could someone please help?

Thanks.

Here is a pic of the question of a transformation of a function http://i54.tinypic.com/28004t1.jpg

So first, the graph moved to the left by 3 units - therefore I added 3 so the function becomes y = sq root. (x - x^2) + 3.

Next, it was flipped about the x - axis, so the function now becomes - sq. root (x - x^2).

Finally it was stretched vertically by a factor of 2 since the highest point went from what should have been -0.5 to -1. Therefore I multiply the function by 2, and the final function should be:

-2*sqroot (x - x^2) + 3 correct?

Hi, could anyone please help me with my phone. So the icon for "weather" has someone moved from page one to page three, I don't know how to bring it back to the first page. I tried pressing till it wiggled, but when I slide it to page 2, it goes back to page 3 immediately after it stops wiggling. There is space available in both page 1 & 2. Thanks a lot.

Find the derivative of the function: y = cos [ ( 1 - e^4x) / (1 + e^4x)]

So I recognized this as the cos u, where u is : ( 1 - e^4x) / (1 + e^4x)

First I took the derivative of cos u, which is - sin u. then I looked for the derivative of u, which I did the following:

[(1 + e^4x)*(1 - 4e^x) - (1 - e^4x)*(1 + 4e^4x) ] / ( 1 + e^4x)^2

I expanded, then put the like terms for the numerator which ended up being - 6e^4x, denominator remained (1 + e^4x)^2.

So the final answer should have been:

numerator 6e^4x * sin [( 1 - 4e^4x) / (1+e^4x)]

denominator ( 1 + e^4x) ^2

however, I was marked wrong on the online assignment! I don't see where the mistake is. anyone could help?

y = 7 sec x

P = ( pi / 3, 14)

thanks for your help

part 1:

f (x) = 5 / ( 2 + e^x)

a. ( 0 , infinity)

b. x cannot be 2

c. ( - infinity, infinity)

d. x cannot be 0

part 2.

f(x) = 1 / (1 - e^x)

a. x cannot be 0.

b. x cannot be 1.

c. ( - infinity, infinity)

d. ( 0 , infinity)

My opinion:

for part 1, 2 + e^x cannot equal to 0, so e^x cannot equal to -2. If I recall correctly, e is never negative, therefore the correct answer should be ( - infinity, infinity).

for part 2, I'm confident that the answer should be x cannot be 0 because it would result in 1 - e^0, which would be 1 -1 and have a 0 for the denominator.

Could someone please let me know if I'm right? Especially on the first one, which I am not too confident in my answer.

Thanks.

Hi, could somebody please help me with this question?

Find all real solutions of this equation:

[ ( x + 9) / ( x - 2 ) ] = [ 7 / ( x + 2) ] + [ 44 / ( x^2 - 4) ]

Thanks a lot!

Equation is 4x^2 + 49y^2 = 196.

Part a) Find dy / dx using implicit differentiation. My answer is: dy / dx = -8x / 98y

Part b) Solve the equation explicitly for y and differentiate to get dy / dx in terms of x. (consider only the first and second quadrants for this part).

I don't know how to do part b. Someone please help?

A baseball diamond is a square with side 90 ft. A batter hits the ball and runs toward first base with a speed of 19 ft/s.

(a) At what rate is his distance from second base decreasing when he is halfway to first base?

(b) At what rate is his distance from third base increasing at the same moment?

An object with weight W is dragged along a horizontal plane by a force acting along a rope attached to the object. If the rope makes an angle θ with the plane, then the magnitude of the force is given by the following equation, where μ is a constant called the coefficient of friction.

F = μW / [ μ sin (θ) + cos (θ)]

part a: Find the rate of change of F with respect to θ.

part b. When is this rate of change equal to 0?

part c. If W = 30 lbs and μ = 0.6, draw the graph of F as a function of θ and use it to locate the value of θ for which dF / dθ = 0. (Round the answer to two decimal places.)

Thank you very much!

Find an equation of the tangent line to the curve at (0,0)

y = ( 3x) / (x + 2)^2

Thanks a lot for helping!

What is

lim (1 - x - x ^2) / ( 3x^2 - 2)?

x--> - infinity

Does it even exist? Thanks a lot.

Find the values of a and b that make f continuous everywhere

f(x) =

{ (x^2 - 1) / (x - 1) if x < 1 }

{ ax^2 - bx + 4 if 1 < or = x < 3 }

{ 4x - a + b if x > or = 3 }

Please post answers as fractions.

thanks

Find an equation of the tangent line to the curve at point (5, 4).

y = (x -1) / (x - 4).

y = ________________ ?

Thank you

Let f(x) = 1 + x^2 + tan ( pi*x / 2), -1< x < 1.

a. Find f inverse (1)

b. find f (f inverse (5)).

I think for b, it's just 5 because the two f's cancel right? I can't seem to find the solution for part a.

From this balanced equation:

4 NH3 + 5 O2 ---> 4 NO + 6 H2O

What mass of H2O is produced from the reaction of exactly 500 L of NH3 measured at 255 celsius and 3.00 atm? (Assume there's an excess of O2).

The answer is 935 g. Could someone please provide the steps in obtaining this answer? Thanks.

Part 1. Dimethymercury, (C2H6)Hg, is a highly toxic volatile liquid with a vapour pressure of 58.8 torr at 23.7 celsius. A 0.200 g sample of liquid dimethymercury is placed in a sealed vessel intially containing pure N2 gas (Nitrogen gas) at 0.965 atm at 23.7 celsius, and allowed to vaporise completely at this temperature. After vaporization, the pressure in the vessel was measured to be 1.011 atm. How many grams of nitrogen gas are present in the vessel?

I think there is a mistake in the given answer of 0.510g, but I still cannot figure out how to do this. What I did was figure out the moles of C2H6Hg by doing: 0.200g x Molar Mass = 8.70 x 10 ^ -4. From that, I did the mole fraction, 1 - Moles of C2H6Hg and got 0.999 moles of N2. I then multiplied moles of N2 to the molar mass, 0.999 x 28 = 27.97 g = 28.0 g in three significant figures.

Is that correct?

Also, part 2 of that question is:

In the above experiment the dimethylmercury vaporized completely leaving no liquid phase behind. This is because the vessel is large enough to accommodate the entire 0.200 g sample as vapour. If the vessel was somewhat smaller, only part of the sample would vaporize. What is the minimum volume of the vessel in which the entire 0.200 g sample will vaporize leaving no liquid phase?

Second part isn't that important to me because I don't understand the first, if you do not want to waste time answer the second one that's okay. But please, if you know how to do the first help me out. Thanks a lot.

Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of He is present in a helium-oxygen mixture having a density of 0.518 g/L at 25 celsius and 721 mmHg?

Thank you very much for helping.