Primarygun

For volume rotated, if two curves have more than 2 intersection pt., we must figure out in which region one is above the other, right? thanks

Thanks for kind reply to my question. [math] \int_a^b f(x) \,dx = \int_a^b f(y) \,dy [/math] This is where a dummy variable could be used. But, put y=-x and f(x)=x^2, from the formula above, We must keep the limits constant, However, this gives a different answer.Why?

Here I got a conceptual problem rarely mentioned by my teacher. When we try to figure the value of a definite integral, the general method is to find out the expression(value) of the indefinite integral, right? but, when we change the dx to d(-x), a must change must be produced correspondingly, that's changing the upper limit and lower limit, right? [math] \int_a^b x \,dx [/math]

The decomposition of this nitrate at room temperature should be slow, right? Before your tellings, I didn't think of any possibility that silver oxide would do so much hurts to us. My brain was covered by the gravity of the serious corrosion by halogens. http://en.wikipedia.org/wiki/Sodium_carbonate Anyone knows why sodium carbonate is more harmful than silver nitrate? On the right hand side, the harmful level is 2 while that of silver nitrate is only 1. Have a look at this. http://en.wikipedia.org/wiki/NFPA_704

Does this suggest that HF is more reactive than Fluorine?

A bottle of silver nitrate solution is labelled "corrosive". That's what I read from my book and web sites. However, when I was carrying out the silver nitrate test, my teacher did not give my class any pieces of advice. Here, I found a web site [you don't need to really browse it] http://www.jtbaker.com/msds/englishhtml/S2282.htm

Besides Teflon and fluoride salts, what kinds of substance do not react with fluorine?

(1) Heating "light" reactive metal in air, such as lithium would greatly increase the mass.

Is fluorine reactive enough to react with gold? Regarding this reaction, does plastic have a higher tendency to react than gold?

My computer got a terrible error. More Precisely, there are two errors. My computer reboots on and off. This is the terrible symptom I experience. When I check the BIOS, I noticed two things. There are two pre-boot errors. Pre-boot error: Memory size decreased Pre-boot error: Keyboard not functional Does anyone have idea? I've bought a new keyboard with the connection USB instead of the old PS2. Recently, my computer reboots even at the BIOS panel. I am afraid the situation is worsening.

Mr Lam borrowed $3M from a bank to purchase an apartment. The bank offered him an interest rate of 4% and a payment period of 15 years. The monthly payment is $22191. Would you like to give me a calculator to find out whether the actual total payment? I wonder if it is = 22191*12*15

yes, I agree with you. I think the question lacks information for the finding. The line joining from the tip of the triangle is not restricted to any point on the horizontal line.

I could remember that a book talks about this question, but in reproduction. It said that zygote divides within the cytoplasm to form a ball of cells instead of creating new "external cells" is to reduce the size of cells. You may have a book at this chapter,.

The overall result is that Al is oxidized. How about each step? My book said oxygen is first produced. I wonder about this.

That's Biology.

How do you distinguish between longitudinal section, vertical section and transverse section? It occurs to me that I've no idea. Thank you.

In Al anodization, object made of aluminium to be anodized is anode. In my text book, it said that oxygen is produced and oxidize aluminum to Al2O3. But, Al is a stronger reducing agent than OH-, why is OH- oxidized instead?

I could find the first several digit of my password by a IE recovery. However, the software is subject to the trial, so I couldn't find the entire one. Do you know any software which offers full functions for 1 day , or else instead of partial functions? I doubt whether the password is in my regedit? [Edit again:] Thanks everyone, I downloaded the Internet Password Recovery Toolbox and found my password.

Recently, I lost my password for a web site. Only the IE saved the password for me but not my firefox. Are there any softwares allowing me to check my password recorded just like I can check mine in firefox? Thanks

The smell persists after boiling or freezing.

When I was young, my nose bleeds very frequently. From the past 10 years, no serious bleeding occurs in my nose. I think your nose will recover later. Perhaps you should have a doctor check

I think it's only my home. Oh I forgot insects may be one of the sources. I've bought a water filter several years ago, and it was said that the duration of its ability would not last till now. No wonder that it is out of order, but my mom’s friend's suggestion for this type. The filter rod couldn't be washed or either replaced. It costs my family about 200 pounds at that time. Personally, do you think that the smell could be entirely removed? I was scolded by my grandmother, for asking about buying distilled bottled water and the suggestion of notifying the supplier. I don't know whether the culture is the same in Europe, my grandmother likes to talk to me loudly once I request again. What I could do now is teasing her every time she prepares soup for me and my brother. Actually, she does it everyday, so I say it everyday, asking her not to include salts in the soup as the water already tastes like sea water. The problem here is she doesn't feel the smell, but my brother does, same as me, so the trouble is still here./ I wanna get some evidences to let her know the fact. What are your suggestions? How about distilling water? Expecting salts leaving out. But how long does it take to evaporate a beaker of sufficient water in order to give strong evidence?

I don't know why, tap water in my home has a undesirable smell which I couldn't tolerate. The smell is like fish smell. I've tried using different utensil to boil the water, but the smell still persist. I've decided to drink less of it each day. Does anyone know how to remove the smell? I don't want to be thirsty all the time.

OK. It is the same as the notation of sin pi =0 Thanks But what if f(x)=x+cosx f(pi)=pi radian-1 So shall we leave the answer in this form or (pi-1)

But isn't the answer = pi radian?