/sci/ - Science & Math

Hello /sci/. I have a simple math question and all I need is a quick "yes" or "no".

Let <span class="math">(G, +)[/spoiler] be a group. Let <span class="math">g_1 \in G[/spoiler] and let <span class="math">g_2 \in G[/spoiler]. Is it always necessary that <span class="math">(g_1 + g_2) \in G[/spoiler]?

Wikipedia says closure is a group axiom, but my teacher didn't include it in his lecture. I tend to believe wikipedia, but I have no idea and need reassurance. Thanks in advance.

Why are scientist so jelly of engineers and non educated folk that are mechanically gifted?|

http://en.wikipedia.org/wiki/George_Stephenson#The_miners.27_safety_lamp

where can i use a texas ba 2+ calculator online?
i need it for my finance assignment...please and thanks

This is like 13th grade shit people, surely one of you knows the answer.

I will be forever in your debt, enjoy flowers.

Doing a meterology assignment and I was looking for some help.
The total surface are of the average human body is about 1.5m^2.

a) what is the radiated power per unit are if the skin has an average temperature of 22 degrees celsius.


What I have gotten so far is the total power being 4.29x10^19. Using the stefan boltzman. Would I just divide by 1.5M to get the per unit power outage due to 4.29x10^189 is already in watts/m^2?

>mfw spend hours a day on my upper level math classes and still struggle. Don't show up to other classes and still have 100%.

Assuming a is even and b is odd, prove:
gcd(a, b) = gcd(a/2, b)


A real proof.


Pic related: Tulips

I'm trying to find the region for which log(z+1) is analytic. We know that z+1 is entire from cauchy riemann equations. Using the principle branch for log, it's analytic on the set C \ {x+iy | x=<0, y=0} ( this is just C without the negative real axis ). Do we simply shift the set over to the left to account for the +1 in the function to find its region of analyticity?

DO WE HAVE ANY OBSERVATIONS OF A BLACK HOLE? ANY DATA AT ALL? OR JUST THEORETICAL BULLSHIT. ALSO, HOW FAR AWAY DOES A BLACK HOLE TUG YOU IN? HOW COME WE DON’T FEEL IT HERE ON EARTH?

And you probably think it is stupid question but i am not a physacist like you but why doesn't gravity attract gravity?

does studying geology mean you have to choose between evil (mining, gas and petroleum) and being a hippy (environmental stuff) or being a genius (academia)

Hi. I have some flowers in the backyard. I know a little genetics from high school. I have 2 pinks, 1 white, and 1 red snapdragon. I can cross any 2. The flowers of snapdragons are red, pink or white. Crossing homozygous red snapdragons with homozygous white snapdragons produces offspring that have pink flowers. Which of the crosses would produce the highest percentage of white flowers for me?

1 + 1 /sci/?

Sorry /sci/ I've asked this question before on here but I had to go and wasn't able to see the answer but anyway.

Lets say you produce sperm from masturbation or a wet dream. Can any of that sperm go on to make a woman pregnant via contamination e.g I touch something and contaminate it with sperm and she touches it and fingers herself? Or is it impossible to make somebody pregnant without penetration?

Yes I am OCD and I keep having this fear that if I cum and go outside that I will make people accidentally pregnant because of a past experience where somebody told me it only takes 1 sperm cell in order to make someone pregnant so you should not masturbate. Washing hands also does not help because I know there is still microbial sperm cells in my clothes and skin.

Thanks.

>kW
>energy

Just wondering about something, is it really true that eating unhealthy food have an effect on your acne? I have heard (this is not from a very good source, more like a random idiot) that as long as you don't eat anything with a lot of fat it's fine. I also heard someone else say that what you eat have no effect on acne. Would love an answer from someone a bit brighter, thanks /sci/

Everything is nothing but complex systems of atoms reacting to one another.

>dealwithit.jpg

>>4776454
Just to clarify, that isn't the OP.

Is there any real use for economics past 1st and 2nd year stuff like interst and annuities?

I really don't see the point. Maybe I'm wrong?

What are two pollutants that destroy the ozone?

hey i got something for you... also if this is the wrong board revert me to another board please:
so i dont often have night terrors and i want to learn why....
my mother said i woke her up yelling for her and then this last night
i yelled,"NO TRINA DONT!"
I dont know why i yelled my sisters name like that.
anyways, so this is like the 7th time its happened in about 5 years...
so ideas?
>pic is nice shut up

>using calculators in mathemathics
>troll spotted

>using calculators in science
>go ahead no one cares

if the absolute value of a varaible (x) is equal to the square root of that negative number to the power of 2 in terms of negative numbers. would give a system of numbers exceedingly greater than -1, is this a true statement?

explain how in an analogous sense, it would also stand true in terms of complex numbers (a + bi) that the measurement using Pythagorean theorem would provide an intuitive imagined sense related to the measurement of size, or if such an imagined sense is possible, acceptable or absurd to "think".

in other terms; explain the relationship between the absolute value of negative numbers and the Pythagorean theorem in terms of complex numbers when used to measure the size of objects both imagined and being learned.

in return I offer only these beautiful tulips.

Is the free market economy, by externalising the environmental and social costs of greenhouse gas emissions is creating the greatest market failure of all time, namely climate change?

okay,
what ipad science/education related useful apps does sci knows/uses?