Rohirm
Fear is a Leash
+85|6110|New Austin, Not
When is this curving up and curving down?

(x^2-24x+136)

I have the derivative, but now what? Its been a while since i did any calc.
JoshP
Banned
+176|5628|Notts, UK
when dy/dx is +ve, the gradient is positive, therefore the graph is curving up, and when dy/dx is negative, it's curving down

solve dy/dx = 0 to find turning points
Kurazoo
Pheasant Plucker
+440|6623|West Yorkshire, U.K

JoshP wrote:

when dy/dx is +ve, the gradient is positive, therefore the graph is curving up, and when dy/dx is negative, it's curving down

solve dy/dx = 0 to find turning points
lol.
Finray
Hup! Dos, Tres, Cuatro
+2,629|5727|Catherine Black

JoshP wrote:

dy/dx
I UNDERSTOOD THIS.

THIS IS DIFFERENTIATION.





......right?
https://i.imgur.com/qwWEP9F.png
Yaocelotl
:D
+221|6589|Keyboard

Sir Schmoopy wrote:

JoshP wrote:

dy/dx
I UNDERSTOOD THIS.

THIS IS DIFFERENTIATION.





......right?
no, dy/dx is related to differential equations. Differentiation are terms "x dx"
Sydney
2λчиэλ
+783|6782|Reykjavík, Iceland.
When the x^2 is positive, it's a smiley face, when x^2 is negative, it's a frown face.

To find when it's curving up or down, differentiate, in this case:

f(x) = (x^2-24x+136)
f'(x) = (2x-24)

And when f'(x) is negative, it's going down, when f'(x) is positive, it's going up.

Last edited by Sydney (2008-11-19 12:30:34)

JoshP
Banned
+176|5628|Notts, UK
dy/dx = f'(x) ....
argo4
Stand and Deliver
+86|5872|United States
find the second derivative f", if that's positive, the graph is concave up(smiley face)if it's negative, the graph is concave down
Winston_Churchill
Bazinga!
+521|6678|Toronto | Canada

argo4 wrote:

find the second derivative f", if that's positive, the graph is concave up(smiley face)if it's negative, the graph is concave down
This

Curving up (which sounds more like concavity that increasing/decreasing) is f'', the second derivative
JoshP
Banned
+176|5628|Notts, UK

Winston_Churchill wrote:

argo4 wrote:

find the second derivative f", if that's positive, the graph is concave up(smiley face)if it's negative, the graph is concave down
This

Curving up (which sounds more like concavity that increasing/decreasing) is f'', the second derivative
f'' is the rate of change of the gradient, i.e if f'' is +ve the curve is getting steeper, and if -ve, it's getting shallower
Winston_Churchill
Bazinga!
+521|6678|Toronto | Canada

JoshP wrote:

Winston_Churchill wrote:

argo4 wrote:

find the second derivative f", if that's positive, the graph is concave up(smiley face)if it's negative, the graph is concave down
This

Curving up (which sounds more like concavity that increasing/decreasing) is f'', the second derivative
f'' is the rate of change of the gradient, i.e if f'' is +ve the curve is getting steeper, and if -ve, it's getting shallower
Umm, no?

Positive means it is facing up... \/ like that, but a curve... and negative means it is facing down /\, like that.
Vub
The Power of Two
+188|6433|Sydney, Australia
When the first derivative is positive, the curve is sloping up i.e. /
When the first derivative is negative, the curve is sloping down i.e. \
When the second derivative is positive, the curve is concave up i.e. \_/
When the second derivative is negative, the curve is concave down i.e. /^\
JoshP
Banned
+176|5628|Notts, UK

Winston_Churchill wrote:

JoshP wrote:

Winston_Churchill wrote:


This

Curving up (which sounds more like concavity that increasing/decreasing) is f'', the second derivative
f'' is the rate of change of the gradient, i.e if f'' is +ve the curve is getting steeper, and if -ve, it's getting shallower
Umm, no?

Positive means it is facing up... \/ like that, but a curve... and negative means it is facing down /\, like that.
what vub said
Ryan
Member
+1,230|6782|Alberta, Canada

Good thing I'm not continuing with AP math after the next semester. Im taking grade 12 math next semester in grade 11, and I'm going to skip calculus.
sad fish
Member
+7|5629|California

Vub wrote:

When the first derivative is positive, the curve is sloping up i.e. /
When the first derivative is negative, the curve is sloping down i.e. \
When the second derivative is positive, the curve is concave up i.e. \_/
When the second derivative is negative, the curve is concave down i.e. /^\
^ This is the correct answer
Winston_Churchill
Bazinga!
+521|6678|Toronto | Canada

JoshP wrote:

Winston_Churchill wrote:

JoshP wrote:


f'' is the rate of change of the gradient, i.e if f'' is +ve the curve is getting steeper, and if -ve, it's getting shallower
Umm, no?

Positive means it is facing up... \/ like that, but a curve... and negative means it is facing down /\, like that.
what vub said
Which is what i said.  We were talking about f'' and its exactly what i said it was, he said the same thing as me but included f' as well
Mitch
16 more years
+877|6464|South Florida
For some reason i read this thread title as "Cactus help"

o.o

Last edited by Mitch (2008-11-19 15:54:42)

15 more years! 15 more years!
JoshP
Banned
+176|5628|Notts, UK

Winston_Churchill wrote:

JoshP wrote:

Winston_Churchill wrote:


Umm, no?

Positive means it is facing up... \/ like that, but a curve... and negative means it is facing down /\, like that.
what vub said
Which is what i said.  We were talking about f'' and its exactly what i said it was, he said the same thing as me but included f' as well
which is what i said

we were all getting confused by our different wording, lulz
Winston_Churchill
Bazinga!
+521|6678|Toronto | Canada

JoshP wrote:

Winston_Churchill wrote:

JoshP wrote:


what vub said
Which is what i said.  We were talking about f'' and its exactly what i said it was, he said the same thing as me but included f' as well
which is what i said

we were all getting confused by our different wording, lulz
Well, if f'' is negative its not getting shallower, its facing the other way lol

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