/sci/ - Science & Math

>>6468698
Ive always hated the idea of dyson spheres and felt them stupid.
Why not simply use nuclear fusion as well as harnessing the geothermal energy of any planets with molten cores? Your energy needs are spread out over a solar system now anyway. You dont fucking need to take the most direct, centralized approach that requires an obscenely difficult construction/sattelite project and blotting out your sun for energy.
Also, how would harnessing any significant portion of its energy via a dyson structure not kill literally everything but you on your home planet, now that theyre getting a significantly smaller portion of solar energy pumped into their ecosystem?

I'm translating a source code that I wrote from C++ to Java, but Java is brand new to me. For some reason, the output of this code is the entire array of integers instead of only the prime numbers in the array. Here is the code I wrote:

//Sieve of Eratosthenes

package sandbox;

public class Sieve {

public static final int SIZE = 120;

public static void sPrint(boolean[] max){
int i;
for (i = 2; i < max.length; i++){
if(max[i] == true);
System.out.print(i + " ");
}
}
public static void sInit(boolean[] max){
int i;
for ( i = 0; i < max.length; i++ ){
max[i] = true;
}
}
public static void sSieve(boolean[] max, int m, int n){
if ( m * n < max.length){
max[m*n] = false;
sSieve(max,m,(++n));
}
else if(m < n)
sSieve(max,(++m),m);
}

public static void main(String[] args) {

int m = 2, n = 2;
boolean[] arr = new boolean[SIZE+1];

sInit(arr);
sSieve(arr,m,n);
sPrint(arr);
}
}

If the square root of any real number has both a positive and negative value, how come the sum of two roots doesn't have 4 different values and so on?
How come we ignore the non-negative roots?
I'm sure I'm fucking retarded, but I just don't understand it.

1. Consider the power series:

<span class="math">\sum_{n = 1}^{\infty}\frac{n(4x-2)^n}{3^n}[/spoiler]

a) Compute the power series' Radius of Convergence.

Alright, so this comes out as inconclusive with the Ratio Test on Wolfram:

http://www.wolframalpha.com/input/?i=seriesSum%28n%284x-2%29^n%2F3^n%2C+n%2C+1%2C+infinity%29

My question is about why it is considered inconclusive With the Ratio Test. I've done the math several times and end up with:

<span class="math">-\frac{1}{4}< x < \frac{5}{4}[/spoiler]

The Ratio Test states that:

If <span class="math">\lim_{n \to \infty}\left| \frac{a_{n+1}}{a_{n}}\right|=1[/spoiler], the Ratio Test is inconclusive; that is, no conclusion can be drawn about the convergence or divergence of <span class="math">\sum a_n[/spoiler].

My other thought was that since I got a range of values, the Ratio Test is inconclusive. I don't know, though. I'd like some other opinions here, and maybe a second pair of eyes to see if I'm screwing something up.

can anyone get this integral?
<span class="math">\displaystyle \int \cos x(1+sin^2x)dx [\math][/spoiler]

I still have my Princeton rejection letter from back in march. It is sitting in an otherwise empty drawer.

I have gone out of my apartment exactly twice since March 23rd, 2012. I believe I am near having an absolute mental breakdown. A breakdown of all that is me.

Princeton was the home for me. Princeton has always been my home. I tried my hardest throughout the awful, gut-wrenching experience that was K-12 and was near as perfect as everything as I could be. Top 5% GPA, a plethora of ECs, passion and love for my study of choice (computer science) and a special kind of love for Princeton.

So why did they reject me?

I did everything, everything I was told I needed to do to succeed. So why has this happened to me?

I wanted to study in Princeton for 10+ years. Afterwards I wanted to become a professor and spend the rest of my days in the one place that I loved.

How do you deal with the rejection, /sci/?

I don't know what to do with my life anymore

>>4661724
You read it wrong, but Jesus Christ that would be horrifying.
How about this, though
>Standing in line at a cash register
>Tulpa starts stroking you

What if there was absolutely nothing, and then something same from nothing because of some quantum asspull or something, then that caused the Big Bang?

>Professor for my Calc 3 class isn't a professor, it's a grad student.
>The first thing he says when he enters the class is "a class full of men, we need to give women more scholarships".
>He doesn't print out a syllabus, because he doesn't want to waste paper. (Who fucking cares, paper literally grows on trees)
>He wears loose and untucked dress clothes, plus sandals.
>He has some sort of hippie beard thing.
>He can't teach well at all.
>Student corrects his errors and says "just trying to keep you guys on your toes".
>The quiz he gives out is difficult to read, since it's in his messy and unintelligible handwriting.
>Questions on the quiz on information that was taught literally the same class he gave the quiz.
>After class I am trying to see how to do a problem and he admits that actually wrote it incorrectly.
>He doesn't omit the question.

What the fuck is this shit? This is where my tuition goes?

I actually used to know how to do math like that OP
turns out you need none of that ever again ever

>mfw 1% goes for science and 99% for energy

not even mad.

I just want to live long enough to clone my teenager body and then transplant my brain there

1 light year = 9 467 280 000 000 km

you are forever alone.

Does people without absolutely no mental disorder exist?

do you recommend marijuana for social phobia ?

why are there people who say that nature and the universe are different things?

>>3107959
>light has no mass