Hi,

I wondered if you would be able to help.  I've set up a for-loop that substitutes values of b into a given function (dependent only on b).

When substituting the values of b into the function f the values of f decrease to a point and then the values of f begin to increase.  I want to establish the interval in which this change occurs, i.e. the minimum of the function.

Below I have included a code similar to our situation:

Hi, using a solution of u that I have already calculated from an ode (by the method of multiple scales), how would I plot a phase portrait of u' against u??  All help is greatly appreciated.  Many thanks in advance.