# I need help on how to find the maximum

1. Dec 1, 2011

### Black-Mind

I'm new on matlab and I need to find the value that make the derivative of a function = 0 in order to find the maximum of my function

I started by defining the variable T

>> syms T

Then I but my function

>> f=((((cos(T))^2+(sin(T)*cos(T)))^2)+3*(((sin(T))^2+(sin(T)*cos(T)))^2))^(0.5)

Then I diffrentiate the function with respect to T

>> diff(f,T)

But know i want to find the value that make my function equal to zero but I cant figure it out espically that I'm new on matlab

If anybody can help me I'll be thankfull

2. Dec 1, 2011

### Simon Bridge

help findpeaks

http://www.mathworks.com/help/toolbox/signal/ref/findpeaks.html

When you use matlab for this you are representing a continuous function by a discrete one. For this reason, the exact point of the extreema may not have been included in your data set. So - differentiating the function and looking for the points that are equal to zero will usually be unhelpful.

3. Dec 3, 2011