Help me please, tysm!

1. Find the moving trihedral and the curvature at any point of the curve R(t) = cost i + sint j + k. 2. Let R(t) = , sin 4t i - bcos?(2t) j + 2t k. Find the moving trihedral of the curve of R(t) at t = 0. 3. Let the curve C be traced by the vector-valued function R(t) = cos( nt ) i+ nt j + sin(at) k. Find the moving trihedral of C at the point where t = 1