Homework Help: Minima of sin function with domain (a, b)

1. Aug 6, 2012

ndesk1900

1. The problem statement, all variables and given/known data
Consider the function f(x) = sin (x) in the interval x ∈ (p/4, 7p/4). The number and location(s) of the local minima of this function are?

2. Relevant equations

3. The attempt at a solution
I have managed to get one of the minimas (i.e. 3p/2), however i am unsure about the the minima. If x ∈ [p/4, 7p/4], then it would be p/4 however since x ∈ (p/4, 7p/4) and p/4 is not part of the domain not sure what the minima would be. Here is an image to denote the same idea.

*Please note p is pie here.

2. Aug 6, 2012

Staff: Mentor

This character - π - is pi, not pie.

For the function on its restricted domain, there is one maximum (plural is maxima) and one minimum (plural is minima). The usual techniques of calculus can be used to find these critical points.

3. Aug 7, 2012

RGV