Calculate X when derivative is zero

Hello, I want to calculate the first X instance when the function derivative is set equal to 0. I understand the solve toolbox will do this but the method is unclear. Will someone describe this procedure?

Gavin.

[John D'Errico]

Read the help for solve. Not that there is NO assurance that solve will yield ALL solutions. As well, solve will often find complex solutions. How you define "first" when a variable is complex is difficult to do.