Math Is Fun Forum
You are not logged in.
- Topics: Active | Unanswered
Pages: 1
#1 2024-03-23 05:05:20
- mathxyz
- Member
- From: Brooklyn, NY
- Registered: 2024-02-24
- Posts: 1,053
Determine Local Minimum Value
Given f(x) = -x^3 + 12x, a local maximum value of 16 is said to be at 2.
Determine the local minimum value.
Note:
Does the local maximum value of 16 at 2 mean point (2, 16)?
If so, how does the point (2, 16) help me find the local minimum?
DO NOT USE CALCULUS.
Offline
#2 2024-03-23 05:42:19
- Bob
- Administrator
- Registered: 2010-06-20
- Posts: 10,619
Re: Determine Local Minimum Value
Because it's a odd function so you can use the rotational symmetry.
B
Children are not defined by school ...........The Fonz
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you! …………….Bob 
Offline
#3 2024-03-24 10:01:16
- mathxyz
- Member
- From: Brooklyn, NY
- Registered: 2024-02-24
- Posts: 1,053
Re: Determine Local Minimum Value
Because it's a odd function so you can use the rotational symmetry.
B
Can you further explain rotational symmetry?
Offline
#4 2024-03-24 14:03:01
- amnkb
- Member
- Registered: 2023-09-19
- Posts: 253
Re: Determine Local Minimum Value
Given f(x) = -x^3 + 12x, a local maximum value of 16 is said to be at 2.
Determine the local minimum value.
since you can't use calculus then they probably wnat you to look at the picture
install the TI-84 emulator on your phone
plug -x^3+12x into [Y1=]
hit 'graph'
select 'calc'
choose 'minimum'
Does the local maximum value of 16 at 2 mean point (2, 16)?
Yeh
If so, how does the point (2, 16) help me find the local minimum?
I think youre supposed to assume mirrored symmetry
max at (2,16)
min at (-2,-16)?
this *is* the min but I don't know how you were supposed to know
THis mirroring doesn't always happen so you can't assume
Offline
#5 2024-03-28 09:53:22
- mathxyz
- Member
- From: Brooklyn, NY
- Registered: 2024-02-24
- Posts: 1,053
Re: Determine Local Minimum Value
FelizNYC wrote:Given f(x) = -x^3 + 12x, a local maximum value of 16 is said to be at 2.
Determine the local minimum value.since you can't use calculus then they probably wnat you to look at the picture
install the TI-84 emulator on your phone
plug -x^3+12x into [Y1=]
hit 'graph'
select 'calc'
choose 'minimum'FelizNYC wrote:Does the local maximum value of 16 at 2 mean point (2, 16)?
Yeh
FelizNYC wrote:If so, how does the point (2, 16) help me find the local minimum?
I think youre supposed to assume mirrored symmetry
max at (2,16)
min at (-2,-16)?
this *is* the min but I don't know how you were supposed to know
THis mirroring doesn't always happen so you can't assume
Where are we going with this situation?
Offline
Pages: 1