The electric potential function for two positive charges, one at $(0,4)$ with twice the strength as the charg at $(0,-1)$ is given by the following function. Complete parts a through d below.

$(x,y)=\frac{2}{\sqrt[\phantom{2}]{x^2(y-4{)}^2}}\frac{1}{\sqrt[\phantom{2}]{x^2(y1{)}^2}}$

b$.$ For what values of x and y is the potential $$ defined? Select the correct choice below and fill in any answer boxes within your choice.

A$.\{(x,y)$:$(x,y)0,-1\}$

$($Type an ordered paik. Use a corrma to separate answers as needed$)$

B$.,$

$$

$$

$($Use a comma to separate answers as needed.$)$

C$.$

$($Use a conma to separate answers as needed.$)$

D$.R^2$

c$.$ Is the electric potential greater at $(2,3)prop(3,2)?$ Choose the correct answer below.

A$.(3,2)$

B$.(2,3)$

d$.$ Describe how the electric potential varies along the line $y=x.$ Choose the correct graph below