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homework help

mlin-3
1-Newbie

homework help

i am trying to plot this function S(R) but it keeps saying that it does not converge to a solution. based on the homework it says that it should be an exponential decay to zero but i don't know why it is not working out here. anyone know what to do? my functions and plots are solely just following my teacher's directions but it seems that it doesn't work as easily as it seems.

3 REPLIES 3
LucMeekes
23-Emerald III
(To:mlin-3)

Hi Michael,

Does a0 (here shown as a unit, because it's in blue) have the correct value? (if I request its value, it's someting like 5*10^-11 m (metres yes!) So it's the only thing in your equations that has a unit. And you cannot have someting with a unit as argument to the exponentiation function exp()).

Your function S integrates on three variables, ra, theta and phi, ra (squared) and theta (the sine of...) are in the integrand, but phi is not there. Is that intentional?

You defined two functions psi (psi1sA and psi1sB) each a function of three parameters; you appear to be wanting to use those functions in the integrand, but fail to name the correct parameters. If I were Prime I would refuse to compute that integral....

I think you have some corrections to do. Don't hesitate to come back if after that it still does not converge.

Success!

Luc

ok...i'm not really sure how to use this hardware so i will see what i can do as far as adjustments. so are you telling me that i can't have a0 in the exp?

LucMeekes
23-Emerald III
(To:mlin-3)

No, it's not that. If a0 has a unit (example m) then your ra should divide it out (= also have a unit m). The argument to the Exp() function must be unitless.

And likewise, for the other psi function R must have the unit m as well

Luc

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