okay here's the equation: In a certain molecular structure, the total energy E between two ions is given by E= (-5.6/r) + 10e^(-r/3) where r is the distance seperating the nuclei. now i already sketched the graph but i don't know how to find the domain of E, or find values of r that make sense in the problem situation, or find the realative maximum or minimum values or the total potential energy on the interval (0, ∞) . the y in that interval is supposed to be infinite in case you can't tell what it is. i tried to just look on the table but y never equals zero on there so im lost. then i tried to just stick in zero for y on the equation. i got stuck .