All categories - 28 June 2007

2007-06-28 16:09:16 · 1 answers · asked by Anonymous in Physics

1) Prove the identities for sin(u+v) and cos(u+v) . By using Euler identities.


2) To prove the identities for sin(u-v) and cos(u-v), start with e^i(u-v)= e^iu e^-iv and repeat.


3) (Euler identities)

e^ix = cos(x) + i sin(x) = cis(x)
e^-ix= cos(x) -i sin (x) = cis(-x)

a) Use the fact that cos (x) and sin(x) are periodic with a period of 2 pie. Recall that a fuction f (x) is periodic w/ period T if f(x + T) = f(x). The exponential form of a complex number can thus b defined as z=re^10 , where r and 0 are the modulus and argument of z, respectively.

b) Treat the Euler identities as a 2 times 2 system of linear equations in sin (x) and cos (x) and solve the system. That is, find sin (x) and cos (x) in terms of e^ix and e^-ix. Verify that these representations of sine and cosine are purely real by taking their complex conjugates.

2007-06-28 16:09:10 · 1 answers · asked by Anonymous in Mathematics

I tried to make a "Magic Movie" earlier today and the audio kept cutting out. Also, sometimes the video image "froze". The amount of RAM is 512 MB - do I need more, or do I have a problem with my Firewire cable, or both? The computer's clock speed is 1.5 GHz, and I think the hard drive speed is 4,200 rpm, but it might be 5,200 rpm (not quite sure at this time - will check later). Any help? I'm trying to make a basic music video, and no sound = this ain't right! Help!!! Thanks!!!

Forgot - all programs other than the video recording program were closed.

2007-06-28 16:09:00 · 2 answers · asked by Paul Hxyz 7 in Laptops & Notebooks

i always wondered how does it feel to be fat?
and dont u ppl go off cussinb me and sayin im mean im mean...im just askin...

thanks

2007-06-28 16:08:55 · 11 answers · asked by Anonymous in Other - Skin & Body

Why dont they just do like me and shoot it up, lol.

2007-06-28 16:08:53 · 12 answers · asked by Anonymous in Other - Cars & Transportation

My mom asked me if I would go with my dad to drop her off to help him with the drive. I really dont want to go but I feel bad not helping him out. All my weekends in July are busy this will be my one free Saturday. Should I go? I feel guilty not helping. He is getting old.

2007-06-28 16:08:50 · 3 answers · asked by confused26 2 in Family

2007-06-28 16:08:46 · 12 answers · asked by Friend 6 in Philosophy

I'm a first timer and want to know how badly waxing is going to hurt. I have let my underarm hair grow fairly long (I heard it needed to be long to be waxed completely), so I can only imagine the pain when it is ripped out by the roots. YIKES!!!!

2007-06-28 16:08:45 · 5 answers · asked by TwinkaTee 6 in Other - Skin & Body

........for using at the range and personal protection?

2007-06-28 16:08:43 · 10 answers · asked by hamdrew729 1 in Hunting

2007-06-28 16:08:29 · 22 answers · asked by Anonymous in Other - Society & Culture

2007-06-28 16:08:17 · 7 answers · asked by Anonymous in Philosophy

2007-06-28 16:08:06 · 23 answers · asked by Anonymous in Polls & Surveys

I told Him I'd follow, He never showed up. Instead my life's going down. No job, no money, bills are do. Got hit by another vehicle today, guy had no insurance and ran from the scene. I'm a loser livee with my ma and pa. Everyone knows I'm a loser. So why won't he help me become a winner. I prayed today before the accident. But the accident still happend. God knows I've been depressed lately. If He loved me a little bit He wouldn't let unfortunate things like this keep happening at such a fragile time in my life.

2007-06-28 16:08:02 · 16 answers · asked by veronica r 3 in Religion & Spirituality

Excluding siblings.

2007-06-28 16:07:50 · 21 answers · asked by Anonymous in Polls & Surveys

Yeah it's a bit embarassing u would think a sixteen year old dude has kissed anyone, but yup it's true I havn't so how does it feel or taste like to be more specific........... Does it differ by race or gender?

2007-06-28 16:07:44 · 26 answers · asked by Gteen 2 in Lesbian, Gay, Bisexual, and Transgender

2007-06-28 16:07:35 · 26 answers · asked by josie 4 in Religion & Spirituality

2007-06-28 16:07:34 · 6 answers · asked by Toves 1 in Mathematics

2007-06-28 16:07:27 · 17 answers · asked by Tublet Want To Try It™ 3 in Polls & Surveys

how are a centimeter, a kilogram. and a milliliterthe same.how are they different explain

2007-06-28 16:07:21 · 9 answers · asked by Winnie 3 in Homework Help

2007-06-28 16:07:20 · 18 answers · asked by Anonymous in Religion & Spirituality

Since I have no friend, I don't have any choice.

Do you think that's just too depressing?

If not, what can I do alone that doesn't seem too depressing?

2007-06-28 16:07:16 · 11 answers · asked by Anonymous in Mental Health

Hey everyone! I'm just wondering just how many people out there are really looking foward to the upcoming Harry Potter film: "Order Of The Phoenix" and the final book: "Deathly Hallows". What are you looking foward to see in the movie (maybe a specific fight or something like that)? What are you hoping to find out in the final book? C'mon tell me what you guys think!

2007-06-28 16:06:56 · 21 answers · asked by Anonymous in Books & Authors

Really. I can't even think straight enough to ask or answer anything. I managed to add everyone's birthday to my online calendar but beyond that... ugh. And it just came upon me kind of out of the blue, this really bad feeling in my chest. What the heck is up with that? I need a gosh-dang funny. Gimme a funny. Now!! I wanna funny!!

2007-06-28 16:06:48 · 20 answers · asked by Anonymous in Religion & Spirituality

OK, so I have another court date. This time it was for driving naked in a state park. The other day I took a little trip to the beach and stretched out on the warm sand and fell sound asleep. I woke up about an hour later to discover that the dang sea gulls had been into my potato chips I had brought along and there was gull poop all over my backside and hair--yuk! I ran into the surf and stripped off my clothes and tried to rinse them out but they still smelled like old fish guts. I stayed in the water for awhile and was wondering where everybody had gotten off to when I hear this huge BOOM! Dang if there wasn't a huge storm coming off the water right for me and I was the last dumba** left on the beach. I figured since no one was around I would just trot over to my truck and drive home. Well I made it to the truck and even drove about three miles before a cop pulled me over (cause I don't have a windsheild) and gave me a ticket to see the judge. Oh, Lord -- what do I do now??

2007-06-28 16:06:42 · 4 answers · asked by Anonymous in Etiquette

some words I remember are--- I will go down with this ship, there will be no white flag at my door=====the song i believe is also the theme song for the new movie called Evening

2007-06-28 16:06:40 · 11 answers · asked by Valerie R 1 in Other - Music

Your thoughts...
good fit or not???

2007-06-28 16:06:28 · 3 answers · asked by #16 1 in Basketball

I never drink soda, and I have been belching for two days. Loud productive man burps!!!

2007-06-28 16:06:25 · 30 answers · asked by Anonymous in Polls & Surveys

Not what I was finding. Thoughts?

2007-06-28 16:06:12 · 4 answers · asked by Anonymous in Mathematics

Ok, I think I've finally decided that I'm going to get a tattoo on my inner wrist. I've thought a lot about this, and I think I like this idea the most. I'm going to get the Zodiac symbol for Leo with my birthday (8-21-82) and my name (Lindsey) on my inner wrist. I'm not sure exactly how it's going to look, but that's the basic idea of what I want. What do you guys think? Be nice please and thanks.

2007-06-28 16:06:05 · 6 answers · asked by Lindsey 3 in Tattoos

Personal favorites always change, but what song and which artist are you LOVING right now?

Thanks for your answers. :-)

2007-06-28 16:05:58 · 17 answers · asked by Venus 3 in Other - Music