Chapter 21, Problem 21.33E

A point charge is at the origin. With this point charge as the source point, what is the unit vector $\hat{r}$ in the direction of the field point (a) at x = 0, y = −1.35 m; (b) at x = 12.0 cm, y = 12.0 cm; (c) at x = −1.10 m, y = 2.60 m? Express your results in terms of the unit vectors î and ĵ.