/sci/ - Science & Math

I'm planning in majoring in math, but I'm not sure if I should do slightly more work and get an econ or physics major as well. Is double majoring EVER worth it?

I dont understand the math behind this, can someone break this down more simply. Or is this just wrong

"You have twice as many female ancestors as male ancestors. You may think that's mathematically impossible but it's not. If every woman has one child and every man who has a child has two and every man who doesn't has zero. Then you end up with twice as many female ancestors."

https://www.youtube.com/watch?v=mDg8sP_atIA&feature=youtu.be&t=6m35s

Alright sci-bros serious question. Let’s say I masturbated in the morning, and my dick still has a little cum on it. I go take a shit in the toilet and maybe my dick touched the inner rim of the toilet seat and some cum got on it.

If my sister sat on the seat later on could she have gotten pregnant? I’ve been scared as fuck for two days. Asking for a friend thanks.

How does /sci/ remember and keep track of a bunch of information from a class in their head?

I'm taking a 4 week partial differential equations course right now. On our first exam today, I couldn't remember some of the basic shit from ODE class I took exactly a year ago but could do the initial boundary value problems just fine.

Because this PDE class is condensed, it feels like concepts are starting to blur together instead of being clear and distinct yet also related. I've made perfect scores on all the homeworks so far but that doesn't seem to be enough to make things properly stick in my brain.

>>10667733
Not too sure, I'm taking a physics course at the moment which isn't math heavy and focuses more on concepts, predictions, with some algebra and trig involved. Everything enough is practical enough to make sense but despite being what I would consider an entry-level course it does have some relatively challenging material in it. Formulas to memorize for different circumstances, as well as using math to find out basic information about the problem. Everything just adds on top of each other and itself which is a lot to keep track of. It's not even what's considering the challenging material. Just practice and you'll become better, fren

why is the derived number of a function equal to the coefficient of the tangent

this is something Ive been using from time to time but I've never been sure why

>>10191657
>3rd year physics and cant for the life of me remember the quadratic equation
At this point I just roll with it and tell people memorizing that shit is beneath me...

So, I have a math test tomorrow, and I'm stressed.

I do well in this class, but this chapter is rough.

What do I do, /sci/?

> be me
>15yo interested as fuck in math and science
>get to high school, go to a mathematics olympiad
> start placing
>2 years later, a pro at olympiads, but stopped doing real math
>Bit by bit start enjoying pure math again

What should I do /sci? Should I quit olympiads and dedicate the time for pure math, or should I still do olymipiads to get into a prestigious university?