Re: max and min
- To: mathgroup at smc.vnet.net
- Subject: [mg87480] Re: max and min
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Fri, 11 Apr 2008 01:46:55 -0400 (EDT)
On 4/10/08 at 2:14 AM, amorales at lme.usp.br (Ary Adilson Morales
Alvarado) wrote:
>How I can to obtain the maximum and minimum values in a function
>like a Sin, but that varying their frequency with the time.
The most direct way to find the minimum and maximum of any
function is to use Minimize. Using Sin as an example, a minimum is:
In[4]:= Minimize[Sin[x], x]
Out[4]= {-1, {x -> (3*Pi)/2}}
and a maximum is:
In[5]:= Minimize[-Sin[x], x]
Out[5]= {-1, {x -> Pi/2}}
Alternatively, you can compute the derivative of your function
and use FindRoot, Reduce, Solve etc. Again using Sin as an example:
In[6]:= Reduce[D[Sin[x], x] == 0, x]
Out[6]= Element[C[1], Integers] && (x == 2*Pi*C[1] - Pi/2 ||
x == 2*Pi*C[1] + Pi/2)
finds all of the minima/maxima