9. A graph of the \( x \) component of the electric field as a function of \( x \) in a region of space is shown in below. The scale of the vertical axis is set by \( E_{x s}=20.0 \mathrm{~N} / C \).
The \( y \) and \( z \) components of the electric field are zero in this region. If the electric potential at the origin is 10.0 V ,
(d) what is the electric potential at \( x=2.0 \mathrm{~m} \),
(e) what is the greatest positive value of the electric potential for points on the \( x \) axis for which \( 0 \leq x \leq 6.0 \mathrm{~m} \), and
(f) for what value of \( x \) is the electric potential zero?