ask me math questions (srs)

[Doraemonster]

What is the probability that the sum of the dots on n thrown dice is k?

[Firepanda]

nah, 1/x from 1 to -1 cancels out because of signed area and ish. i meant, the area produced between -1 and 1 of 1/x^2.

the integral of f'(x) / f(x) w.r.t x is just ln(f(x))

so take f'(x) = 2x and turn it into

0.5(1/x)*(2x/x^2) and integrate by parts

edit: unless u were doing that already

[Spaghettii]

the integral of f'(x) / f(x) w.r.t x is just ln(f(x))

so take f'(x) = 2x and turn it into

0.5(1/x)*(2x/x^2) and integrate by parts

edit: unless u were doing that already

don't know about that method...fuuuu i have a long way to go then, thnx.

[Firepanda]

wait hang on a minute you can just write it as x^-2 and integrate that way easy enough

i only mentioned the other way, which sends you into a huge roadblock, because I thought you had tried everything else

[Spaghettii]

wait hang on a minute you can just write it as x^-2 and integrate that way easy enough

i only mentioned the other way, which sends you into a huge roadblock, because I thought you had tried everything else

i can use the second fundamental theorem of calculus for definite integrals, but i don't know if it works for the areas passing through x = 0. after all, on the interval [-1,1], the area is zero.

[Merauder]

i can use the second fundamental theorem of calculus for definite integrals, but i don't know if it works for the areas passing through x = 0. after all, on the interval [-1,1], the area is zero.

I'm confused about these integrals that pass through zero too

[mr_ben]

32490291 X 0 + lulz = ?

[Spaghettii]

I'm confused about these integrals that pass through zero too

bump for this

[ship_it_crucial]

32490291 X 0 + lulz = ?

http://www.wolframalpha.com/input/?i...X+0+%2B+lulz+=

[Nonopb]

Okay I'm dropping the bomb
















































































































0.9999999999999999999999999999...to infinity = 1
or
0.9999999999999999999999999999...to infinity =/= 1?

[Polamaluisraw43]

0.9999999999999999999999999999...to infinity = 1
or
0.9999999999999999999999999999...to infinity =/= 1?

show this by using infinite series

[JRAK12]

solve a millenium problem


i win again

In b4 op is not a millionaire.

[JRAK12]

0.9999999999999999999999999999...to infinity = 1
or
0.9999999999999999999999999999...to infinity =/= 1?

let x = 0.99999999999999999999999999999999 to infinity
10x = 9.999999999999999999999999999999999 to infinity
10x-x = 9
9x=9
x=1

how about
1=1
=sqrt1
=sqrt(-1x-1)
=sqrt-1 x sqrt-1
= -1

Who will be first to spot the technicality.

[Firepanda]

bump for this

if it doesnt converege then it doesnt converge

[kiwimac]

how about
1=1
=sqrt1
=sqrt(-1x-1)
=sqrt-1 x sqrt-1
= -1

Who will be first to spot the technicality.

sqrt(-1x-1)=/=sqrt-1 x sqrt-1

sqrt(xy)=sqrt(x)sqrt(y) is only true for nonnegative real numbers x and y.

[Merauder]

sqrt(-1x-1)=/=sqrt-1 x sqrt-1

sqrt(xy)=sqrt(x)sqrt(y) is only true for nonnegative real numbers x and y.

can someone prove this?

sqrt(xy)=sqrt(x)sqrt(y) is only true for nonnegative real numbers x and y

[Spaghettii]

Bump

[Spaghettii]

I'm confused about these integrals that pass through zero too

i found out today that the integral does not exist.

[turkey_server]

0.9999999999999999999999999999...to infinity = 1
or
0.9999999999999999999999999999...to infinity =/= 1?

1, by definition of an infinite sum.

[Merauder]

For a proof that it IS true for x,y>=0 I will need your axioms. The proof that it is ONLY true in general is given by a counter example.

x = -1, y=-1

sqrt(xy)=1 but sqrt(x)sqrt(y) = -1.

Sometimes it is true, so a proof cannot be given for all cases. i.e. x=2,y=-2 will give 2i as answer either way. To prove that something isn't "true in general" all you need is a counterexample.

yes it is not true in general, but for non negative real numbers?

[Merauder]

i found out today that the integral does not exist.

if f(0) is not defined you can do something with taylor series I think but I'm not quite there yet

[Spaghettii]

if f(0) is not defined you can do something with taylor series I think but I'm not quite there yet

today i'm learning integration by parts. volumes and the avg. value of a function were all VERY easy. i'm starting to like integrals!

[Merauder]

today i'm learning integration by parts. volumes and the avg. value of a function were all VERY easy. i'm starting to like integrals!

what's your education maybe?

or just learning this for fun?

[Spaghettii]

what's your education maybe?

or just learning this for fun?

prime minister

[turkey_server]

if f(0) is not defined you can do something with taylor series I think but I'm not quite there yet

Doesn't change the fact that it's undefined as stands. If the function were merely discontinuous with finite limits at 0, we'd be able to handle it, but it should be clear that in this case the area goes to infinity. Similarly, if it were say, 1/x, we'd be able to exploit the odd nature of the function to conclude (with a bit of tweaking) that the integral is 0.

[eeeeee!]

whats the square root of this apartment

[Merauder]

whats the square root of this apartment

funny

[Merauder]

For non-negative real numbers one needs a set of assumptions to work from; different classes/books start from different assumptions so I need a basis. Otherwise this is my proof: Obvious. QED.

A more sophisticated proof might look like this:

proof one post higher

doesn't look like you had a lot of trouble proving this

what did you study maybe?

[Deathstriker666]

what is your take on Laplace equations

Lol I would have asked a similar question, were studying that now. OP can only answer highschool math questions.

[MUFC]

I hate all the Analysis courses I've had to take.