a$)$ Express the unit vectors $(i,j,k)$ in terms of unit

vectors $(e_r,e_{},e_z)($i$.$e$.$ basis vectors for cylindrical

coordinates$)$ using an unknown angle $$ in the $xy-$

plane. b$)$ Express the $1000$ lb force going through the

origin and through the point $(x,y,z)=(2,4,4)$ in terms

of the unit vectors $(i,j,k)$ using $=60.c)$ Express

that same force vector in terms of the unit vectors

$(e_r,e_{},e_z)$ using $=60$ Pls include FBD and all steps so I can understand. Thank you.