For you who likes math problems! How is this possible??

2009-03-28 06:49:32

#1

SteikeTa: Member; +153|6757|Norway/Norwegen/ Norge/Noruega

f''(x) = [(25-x)^2 * (25-4x)]'

f"(x) = 2(25-x)*(-1)*(25-4x)+(25-x)^2*(-4) <--- used product and "core rule" (don't know if that's correct in English). Kjerneregelen.

f"(x) = (25-x)(8x-50)-4(25-x)^2

f"(x) = (25-x)[(8x-50)-4(25-x)] <---- where did the ^2 go, and where did the [ ] come from??

f"(x) = (25-x)(8x-50-100+4x)

f"(x) = (25-x)(12x-150)

That's what I'm wondering about. The ^2 in line 3... is suddenly gone in line 4. Looks like they changed it with [ ]. Why/how.... what?

Last edited by SteikeTa (2009-03-28 06:50:07)

2009-03-28 08:13:10

#2

Mitch: 16 more years; +877|6535|South Florida

Yeah... No.

15 more years! 15 more years!

2009-03-28 08:15:14

#3

Uzique: dasein.; +2,865|6480

Thread should be: "For you who likes nerdy tedious boring shite! How are YOU possible?"

_{libertarian benefit collector - anti-academic super-intellectual}. _{http://mixlr.com/the-little-phrase/}

2009-03-28 08:19:44

#4

S.Lythberg: Mastermind; +429|6456|Chicago, IL

since there is another (25-x) in front of the equation, squaring it is essentially the same as distributing through would have been, so they changed it to the distrubuting notation to cut down on the number/degree of terms present.

2009-03-28 08:28:59

#5

Mitch: 16 more years; +877|6535|South Florida

Well personally, i think since there is another (25-x) in front of the equation, squaring it is essentially the same as distributing through would have been, so they changed it to the distrubuting notation to cut down on the number/degree of terms present.

Last edited by Mitch (2009-03-28 08:29:14)

15 more years! 15 more years!

2009-03-28 09:00:56

#6

Shadow893: lel; +75|6702|England

Mitch wrote:
Well personally, i think since there is another (25-x) in front of the equation, squaring it is essentially the same as distributing through would have been, so they changed it to the distrubuting notation to cut down on the number/degree of terms present.

this man knows the truth

2009-03-28 09:02:00

#7

S.Lythberg: Mastermind; +429|6456|Chicago, IL

Shadow893 wrote:
Mitch wrote:
Well personally, i think since there is another (25-x) in front of the equation, squaring it is essentially the same as distributing through would have been, so they changed it to the distrubuting notation to cut down on the number/degree of terms present.

this man knows the truth

ima callin mah lawyer

2009-03-28 09:28:04

#8

david363: Crotch fires and you: the untold story; +314|6749|Comber, Northern Ireland

hax

2009-03-28 09:31:38

#9

ATG: Banned; +5,233|6539|Global Command

tbh;

https://karenswhimsy.com/public-domain-images/hieroglyphics/images/hieroglyphics-2.jpg

2009-03-28 13:31:10

#10

Peter: Super Awesome Member; +494|6412|dm_maidenhead

So you can differentiate using the product rule and chain (the word you are looking for) rule but you can't factorise?
D:
This is madness.

As stated before the (25-x) has been factorised out from both terms. The [] mean multiply what is outside by every term inside.

Last edited by Peter (2009-03-28 13:31:48)

2009-03-28 18:43:37

#11

VicktorVauhn: Member; +319|6402|Southern California

S.Lythberg wrote:
since there is another (25-x) in front of the equation, squaring it is essentially the same as distributing through would have been, so they changed it to the distrubuting notation to cut down on the number/degree of terms present.

Give this man a beer, he is winner.