Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Options
Go to last post Go to first unread
Offline Seçkin USLU  
#1 Posted : 16 July 2019 08:57:05(UTC)
Seçkin USLU

Rank: Newbie

Groups: Registered
Joined: 02/05/2019(UTC)
Posts: 7
Turkey
Location: istanbul

Hi all

İ have an equation like r(x)=1-x^2.

İs it possible to find max value of function.

Regards
Offline Razonar  
#2 Posted : 16 July 2019 12:19:02(UTC)
Razonar


Rank: Advanced Member

Groups: Registered
Joined: 28/08/2014(UTC)
Posts: 384
Uruguay

Was thanked: 193 time(s) in 118 post(s)
Hi Seçkin. Some notes about finding maxs.

maximun.sm (20kb) downloaded 26 time(s).

Best regards.
Alvaro.
thanks 1 user thanked Razonar for this useful post.
on 16/07/2019(UTC)
Offline Seçkin USLU  
#3 Posted : 16 July 2019 13:06:20(UTC)
Seçkin USLU

Rank: Newbie

Groups: Registered
Joined: 02/05/2019(UTC)
Posts: 7
Turkey
Location: istanbul

Hi Ronazar thanks for your answer.

İs it possible to find inverse of max value

For example f(5)=2 ise inverse of 2 equals 5

Thanks
Offline Jean Giraud  
#4 Posted : 16 July 2019 15:08:32(UTC)
Jean Giraud


Rank: Advanced Member

Groups: Registered
Joined: 04/07/2015(UTC)
Posts: 3,887
Canada

Was thanked: 699 time(s) in 547 post(s)
Originally Posted by: Seç Go to Quoted Post
Ä°s it possible to find max value of function.

The derivative method is just a quick lazy approach for convenience.
Derivative operator is symbolic, thus won't work for spline interpolation.
The min/max general method is the Golden Ratio.
You are confused with your next question "inverse"
An InverseFunction is a function that solve the given f(x)
... in preparation
Visit Golden ration posted next few minutes

Cheers.
Offline Jean Giraud  
#5 Posted : 16 July 2019 15:32:39(UTC)
Jean Giraud


Rank: Advanced Member

Groups: Registered
Joined: 04/07/2015(UTC)
Posts: 3,887
Canada

Was thanked: 699 time(s) in 547 post(s)
Originally Posted by: Seç Go to Quoted Post
Ä°s it possible to find inverse of max value
For example f(5)=2 ise inverse of 2 equals 5

... Sorry: don't understand your maths in there.
1. Understand InverseFunction
2. ISA altitude as superb application [won't find in Web]

Solve Inverse Symbolic Suite.sm (94kb) downloaded 11 time(s).
Inst_ISA [Landing altitude PDF].sm (306kb) downloaded 9 time(s).

Offline Razonar  
#6 Posted : 17 July 2019 03:10:27(UTC)
Razonar


Rank: Advanced Member

Groups: Registered
Joined: 28/08/2014(UTC)
Posts: 384
Uruguay

Was thanked: 193 time(s) in 118 post(s)
Originally Posted by: Seç Go to Quoted Post
Hi Ronazar thanks for your answer.

İs it possible to find inverse of max value

For example f(5)=2 ise inverse of 2 equals 5

Thanks


Hi. If you have a max of y=2 that happen for x=5, then you can't invert y=f(x) near x=5, because then x=5 it's a critical point, then you have f'(5)=0, or a limit of the interval or a discontinuity, and the inverse function theorem it's a local theorem and needs f'(x)≠0 in the study interval.

Notice that the inverse function theorem it's easy to see graphically (the function isn't one to one), but very hard to demonstrate, as you can see at: http://people.math.sc.ed...p/InversefunctionThm.pdf

Best regards.
Alvaro.


Offline Jean Giraud  
#7 Posted : 17 July 2019 04:33:16(UTC)
Jean Giraud


Rank: Advanced Member

Groups: Registered
Joined: 04/07/2015(UTC)
Posts: 3,887
Canada

Was thanked: 699 time(s) in 547 post(s)
Revisit your example. The mechanics of Inversing a function is intuitive.
However the maths under the hood belongs to few advanced CAS [Maple World top].
Mathematica will do same, most of the times of different presentation.
Before you do anything with a function => graph.
Please, do not hesitate for more.

InverseFunction.PNG
Users browsing this topic
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.