Why can't CS fa/g/s into maths? They act all superior but

Why are mathfags so smug?

>>57400759
Not smug, just annoyed when csfags talk about maths thinking they're right when they're blatantly wrong.

>>57400746
Why can't you do your own homework?

Math minor here.

Who even cares apart from it looking good on a resume?

>>57400746
how do you do this without a computer?

>>57400974
An answer is 89, I've already done it.
>>57401020
>minor
dropped
>>57401042
Look for patterns in the Fibonacci sequence, you don't need to compute many terms and it can be done easily by hand

>>57400746
Yo math niggers, do this problem with your so called fancy pants equations and shit while I'll have the answer ready before you can get to fib(10)

>>57401062
>brainlet who thinks the power of his computer contributes to his own ""intelligence""

>>57401042
F(n) | F(kn) where k and n are positive integers.

Therefore, as 2013 = 11*183, then F(11) | F(2013).

F(11) = 89 which is prime, therefore 89 is a factor of F(2013)

>>57401062
Good luck computing F(2013) even on a powerful computer

>>57400746
what's the big deal about fibonacci sequence?

I can write a program to calculate the index of a fibonacci number in under 5 mins. Wtf?

>>57400746
Why study algorithms if you're not going to implement them

>>57402851
That's not what the question was asking
>>57402906
It's showing an understanding of the properties that certain sequences/operations have. Without paying attention to such things, we wouldn't have finite fields and consequently wouldn't have public key cryptography

>>57401105
I'm not saying I'm intelligent, I'm most certainly not, but I'm pragmatic

I want to get shit done, not stroke my own ego

>>57400746
>Why can't CS fa/g/s into maths?
what makes you think that ? just because you go to a shitty universtiy ? math classes are part of every decent CS curriculum.

>>57401213
Are you retarded
Do you not understand how fast the native addition operation is
A modern computer can literally do trillions of additions per second

>>57401213
Easily done. Fibonacci might often be used as an example of recursive algorithms, but that's not an efficient way to do it.

Store fibonacci values in an array and go up from F(2) to F(2013) and it becomes linear.

The problem with the Fibonacci sequence is that there is no real solution to the recursive sequence F(n) = F(n-1) + F(n-2). You can't guess the growth rate of it (seems to be between N log N and N^2). You also can't use the formula ( a of n = (alpha)(r of 1)^n + (beta)(r of 2)^n) where alpha and beta are constants and r of 1 and r of 2 are non identical roots found in r^2 + (c of 1)r + (c of 2), where c of 1 and c of 2 are the coefficients of the recursion sequence.

Computer engineering student here.
>The Fibonacci numbers are a function
>Babby's first math tier questions
You are a fucking brainlet, OP.

>>57403061
>>57403073
Fair enough, find an odd prime factor of F(279262929216353) (hint, I know the answer)
>>57402990
>desktop thread
>rice thread
>buyer's remorse
>>57403123
You aren't intended to find the growth rate of it, and lim n->infinity F(n) = 1.61803399...*F(n-1)

>>57403183
A sequence is a function with the domain being the set of natural numbers. Therefore the fibonacci sequence is a function.
The question wasn't intended to be hard, I'm not even that good at maths and I did it.

>>57403200
1

>>57403245
>1
>prime number
confirmed for cs student

>>57403200
If you wish to compute a Fibonacci number at any location, such as at F(2013), you need a solution to the recurrence relation.

Look at the Jacobthal numbers. {0, 1, 1, 3, 5, 11, 21 .. } = W(n) = W(n-1) + 2W(n-2). These have a recurrence relation of ((-1)^n-1 + (2)^n) / 3.

>>57403378
>>57403378
>>57403378
Recurrence solution*

>>57403378
discrete math undergrad detected

>>57403378
>you need a solution to the recurrence relation
No you don't.
And evaluating F(279262929216353) isn't going to happen, (it's a fairly big number)

>>57403061
You're fucking retarded, using addition to calculate the Fibonacci numbers is always slow
>>57403073
that's still not a good way to do it
The fast doubling and matrix exponentiation are the best way to calculate yhem because they have Θ(logn) running time https://www.nayuki.io/page/fast-fibonacci-algorithms

>>57403123
The growth rate of the recursive algorithm is Θ(Φ^n) for time and Θ(n) for space. You have no clue what you are talking about

>>57403863
Fair enough, but I still managed F(2013) fast enough not to perceive a delay after hitting the key and getting the answer with the following:

    static BigInteger fibo(int n) {
        Vector<BigInteger> vals = new Vector<BigInteger>();

        vals.ensureCapacity(n);
        vals.setSize(n);

        vals.add(1, BigInteger.valueOf(1));
        vals.add(2, BigInteger.valueOf(1));

        if(n <3 ){
            return vals.elementAt(n);
        }

        for(int i = 3 ; i!=n+1 ; i++) {
            vals.add(i, vals.elementAt(i-1).add(vals.elementAt(i-2)));
        }
        return vals.elementAt(n);


    }

>>57401155

what does | do?

>>57404010
a|b means that the the integer a divides the integer b

>>57404010
x ∣ y is equivalent to y = x * k , k ∈ ℕ

>>57404309

that's so weird

>>57404521
that's induction. math style.

>>57400775
Ur gay

>>57403907
nice symbols dude

>>57400746

This guy is right.

Yesterday I was writing a RESTful API for a PostgreeSQL database. Suddenly I was wondering: "what if F(2013) was odd?"
I was thinking about this the whole day, unable to work: Odd? Even? Odd? Even?

I think they should really teach such necessary skills.

>>57403378
Yes but exponentiation is amortized logarithmic time at best, plus floating point numbers have limited precision and easily break down for large exponents of non-integers (in the case of fibonacci's recurrence relation).

I love math :)

How do you know that F(n) always divides F(kn)? It's not intuitively obvious.

>>57408491
meant for >>57401155

>>57400746
What does the arrow mean in "N --> N"?

>>57400746
Name 1 thing learning such math is useful for.

>>57408509
It means the function F takes domain from the natural numbers and outputs to the range of natural numbers.

>>57408491
If OP can't prove this himself, then he actually is shit at math and this thread is invalidated

>tfw on the school team for the Putnam this year

>Laplace transform and other complex calculus is required for any circuit work
>BUT YOU CAN'T MATH!
Sorry what? In b4 you went to some shit college where CS is exclusively theoretical.

>>57401042
You used the closed form expression instead.