Find minimum value for coefficient of static friction

[PAstudent]

Homework Statement

Homework Equations

Newton's 2nd Law

The Attempt at a Solution

I was wondering if anyone could verify that I have all the correct vectors or if I am missing any. I just wanted to check before I started trying to derive the equations.
[/B]

 

[TSny]

The directions of F_T1 and F_T2 do not appear to be correct in the first and third diagrams. Are the x-axes in those two diagrams parallel to the inclines?

 

[PAstudent]

Yes