# The "official" math thread **URL:** \ **Category:** Unrelated Discussion\ **Created:** [April 12, 2014, 3:10pm UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364 "2014-04-12T15:10:59Z")\ **Posts on this page:** 17\ **Page:** 2
**Author:** ![jhb8426](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/jhb8426/32/631_2.png) [@jhb8426](https://forums.yoyoexpert.com/u/jhb8426)\ **Post date:** [April 13, 2014, 3:41am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/21 "2014-04-13T03:41:29Z")
> [@stuarttw](#): > > derivative of 2x^2 + 2x = ? Easy but i want to see who knows derivatives… f(x)= 2x2+2x ddxf(x)= ddx(2x2+2x) =2⋅ddx(x2)+2 =2⋅2x+2 =4x+2 ---
**Author:** ![EvanW](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/evanw/32/564_2.png) [@EvanW](https://forums.yoyoexpert.com/u/EvanW)\ **Post date:** [April 13, 2014, 4:01am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/22 "2014-04-13T04:01:31Z")
> [@jhb8426](#): > > f(x)= 2x2+2x > > ddxf(x)= ddx(2x2+2x) > > =2⋅ddx(x2)+2 > > =2⋅2x+2 > > =4x+2 is that how you were taught to take derivatives? My teacher didn’t make us do all those steps, she allowed us to just go from 2x^2 + 2x to 4x + 2 ---
**Author:** ![jhb8426](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/jhb8426/32/631_2.png) [@jhb8426](https://forums.yoyoexpert.com/u/jhb8426)\ **Post date:** [April 13, 2014, 4:11am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/23 "2014-04-13T04:11:00Z")
Ya gotz ta show yer work… ---
**Author:** ![CaliBuddha](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/calibuddha/32/156_2.png) [@CaliBuddha](https://forums.yoyoexpert.com/u/CaliBuddha)\ **Post date:** [April 13, 2014, 4:30am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/24 "2014-04-13T04:30:23Z")
Yeah, jhb, I don’t think they make them show their work like they used to… maybe trying to be more green by saving paper! lol I used to go through soooooo much paper just for math… ---
**Author:** ![EvanW](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/evanw/32/564_2.png) [@EvanW](https://forums.yoyoexpert.com/u/EvanW)\ **Post date:** [April 13, 2014, 4:53am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/25 "2014-04-13T04:53:28Z")
> [@jhb8426](#): > > Ya gotz ta show yer work… Right, but that’s a little like having 1+2+5-6 and simplifying it step by step. It’s just assumed you know the steps in between and stuff. Or maybe it’s like what Miami said and it’s just to conserve paper, who knows. ---
**Author:** ![stuarttw](https://avatars.discourse-cdn.com/v4/letter/s/4af34b/32.png) [@stuarttw](https://forums.yoyoexpert.com/u/stuarttw)\ **Post date:** [April 13, 2014, 11:46am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/26 "2014-04-13T11:46:31Z")
guess i don’t understand derivatives ☹ 😢 :-\ :-[ ??? anyone else want to come up with a harder question? ---
**Author:** ![Philip](https://avatars.discourse-cdn.com/v4/letter/p/96bed5/32.png) [@Philip](https://forums.yoyoexpert.com/u/Philip)\ **Post date:** [April 13, 2014, 11:49am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/27 "2014-04-13T11:49:43Z")
d/dx(definite integral from x to y of (4z^4 dz)) = ? take a guess ---
**Author:** ![abby1371](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/abby1371/32/1075_2.png) [@abby1371](https://forums.yoyoexpert.com/u/abby1371)\ **Post date:** [April 13, 2014, 12:14pm UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/28 "2014-04-13T12:14:52Z")
> [@YoCyanightYo](#): > > Purple because aliens dont wear hats how does he know… ---
**Author:** ![Legyoyo](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/legyoyo/32/995_2.png) [@Legyoyo](https://forums.yoyoexpert.com/u/Legyoyo)\ **Post date:** [April 13, 2014, 4:56pm UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/29 "2014-04-13T16:56:39Z")
> [@nardcopter](#): > > We don’t tolerate that kind of language here on YYE. Legyoyo, please take your potty mouth somewhere else. oh my soul, what a typo, I meant to say “kindness, happiness, rainbows” Egad, I’m so embarrassed ---
**Author:** ![nardcopter](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/nardcopter/32/1335_2.png) [@nardcopter](https://forums.yoyoexpert.com/u/nardcopter)\ **Post date:** [April 13, 2014, 5:56pm UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/30 "2014-04-13T17:56:45Z")
> [@Legyoyo](#): > > oh my soul, what a typo, I meant to say “kindness, happiness, rainbows” > > Egad, I’m so embarrassed You are forgiven. My iPhone often changes kind compliments into comments about drugs, cuss words, and math problems. Their autocorrect really needs some fine tuning. ---
**Author:** ![EvanW](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/evanw/32/564_2.png) [@EvanW](https://forums.yoyoexpert.com/u/EvanW)\ **Post date:** [April 13, 2014, 10:13pm UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/31 "2014-04-13T22:13:40Z")
> [@Philip](#): > > d/dx(definite integral from x to y of (4z^4 dz)) = ? > > take a guess 4y^4 dy/dx? ---
**Author:** ![LinksLegionaire](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/linkslegionaire/32/886_2.png) [@LinksLegionaire](https://forums.yoyoexpert.com/u/LinksLegionaire)\ **Post date:** [April 14, 2014, 12:03am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/32 "2014-04-14T00:03:56Z")
What are you guys studying right now? I’m knee-deep in spring damping and resonance. ![](https://us1.discourse-cdn.com/flex015/uploads/yoyoexpert1/original/4X/4/e/b/4eb1fc774775083e893619c23472b11d1993df90.jpeg) ---
**Author:** ![liife](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/liife/32/1060_2.png) [@liife](https://forums.yoyoexpert.com/u/liife)\ **Post date:** [April 14, 2014, 12:23am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/33 "2014-04-14T00:23:22Z")
> [@EvanW](#): > > 4y^4 dy/dx? This was already answered once, but deleted by a mod. Below is the full solution. ![](https://us1.discourse-cdn.com/flex015/uploads/yoyoexpert1/original/4X/d/1/e/d1ebddba0f03e999badf9e17c90e7b0727f1cd06.png) > [@LinksLegionaire](#): > > What are you guys studying right now? > > I’m knee-deep in spring damping and resonance. For the last few weeks I’ve been working on the following problem: ![](https://us1.discourse-cdn.com/flex015/uploads/yoyoexpert1/original/4X/6/d/c/6dc5befd7f0ecf0c4a7f4377070639ca84eff65c.png) ---
**Author:** ![LinksLegionaire](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/linkslegionaire/32/886_2.png) [@LinksLegionaire](https://forums.yoyoexpert.com/u/LinksLegionaire)\ **Post date:** [April 14, 2014, 12:59am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/34 "2014-04-14T00:59:49Z")
> [@liife](#): > > For the last few weeks I’ve been working on the following problem: > [http://i58.tinypic.com/ea1eh0.png](http://i58.tinypic.com/ea1eh0.png) I assume the first couple of weeks were spent trying to figure out what the question actually is ;D ---
**Author:** ![EvanW](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/evanw/32/564_2.png) [@EvanW](https://forums.yoyoexpert.com/u/EvanW)\ **Post date:** [April 14, 2014, 1:38am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/35 "2014-04-14T01:38:53Z")
> [@liife](#): > > This was already answered once, but deleted by a mod. Below is the full solution. > [http://i58.tinypic.com/2itg8cl.png](http://i58.tinypic.com/2itg8cl.png) Oh right, I see what I did wrong. Since it was d/dx it was the derivative relative to x, so Y was just a constant. ---
**Author:** ![jhb8426](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/jhb8426/32/631_2.png) [@jhb8426](https://forums.yoyoexpert.com/u/jhb8426)\ **Post date:** [April 14, 2014, 1:46am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/36 "2014-04-14T01:46:06Z")
> [@LinksLegionaire](#): > > What are you guys studying right now? Nothing, but I had 2 years of calculus and another couple of quarters of differential equations and then all the physics and fluid mechanics courses that use it all. That’s where I really learned it, but it’s been quite some time since I had to use it and it’s very rusty. ---
**Author:** ![Yossarian](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/yossarian/32/1006_2.png) [@Yossarian](https://forums.yoyoexpert.com/u/Yossarian)\ **Post date:** [April 14, 2014, 5:27am UTC](https://forums.yoyoexpert.com/t/the-official-math-thread/65364/37 "2014-04-14T05:27:30Z")
There’s a pretty good YouTube channel called [Numberphile](https://www.youtube.com/user/numberphile) devoted to discussing math and numbers. They’ve got a lot of really interesting videos if you are into that sort of thing, so it’d probably be worth checking out if you’re in this thread. [Previous page](https://forums.yoyoexpert.com/t/the-official-math-thread/65364.md?page=1)