Using the results of Problem 1.7, show that de r /d = e and de

Using the results of Problem 1.7, show that de_r/dθ = e_θ and de_θ/dθ = -e_r.

Data From Problem 1.7

Show that the unit vectors e_r and e_θ in a cylindrical coordinate system are related to the unit vectors e_x and e_y by

e_r = e_x cos θ + e_y sin θ

and

e_θ = -e_x sin θ + e_y cos θ