Find the direction angles of the given vector. Write the vector in terms of its magnitude and direction cosines as v = v [ (cos a)i + (cos B)j + (cos y)k ]. v= - 8i - 4j + 8k a= degrees (Round to the nearest tenth of a degree, if necessary.) B = degrees (Round to the nearest tenth of a degree, if necessary.) y =degrees (Round to the nearest tenth of a degree, if necessary.) v=[ (cos )i+ cos ()i + cos () k ] (Simplify your answers. Type an exact value for v , using fractions and radicals as needed. Round each angle measure to