# Thread: Dual in Convex problem

1. ## Dual in Convex problem

Hello everybody,

I really appreciate your help to solve this problem.

Thanks

2. ## Re: Dual in Convex problem

Hey msoltanik.

For 1) this is going to be using the definition of trace and spectral decomposition.

Think of the eigenvector decomposition of a matrix and note that the length of the vector is at most unit length with an inequality.

Thanks