Do you mean psi (ψ)? If so, then it's no problem to have a negative value of A. The function ψ(x) will be negative for all or part of its domain, but that is no problem. The wavefunction can be negative, and often is. When the wavefunction is used to determine probability (P = ∫ψ* ψ) or to determine expectation values ( = ∫ψ* Â ψ) then the negative values for ψ present no difficulty at all. See these videos for some additional detail: probability: ua-cam.com/video/Sk3VPtV5bQI/v-deo.html expectation values: ua-cam.com/video/ogscPg1FncI/v-deo.html If you repeat the examples in those videos with a negative function ψ(x), then everything still works out fine.
We are drawing chi against x then we can't take negative values of A
Do you mean psi (ψ)? If so, then it's no problem to have a negative value of A. The function ψ(x) will be negative for all or part of its domain, but that is no problem. The wavefunction can be negative, and often is. When the wavefunction is used to determine probability (P = ∫ψ* ψ) or to determine expectation values ( = ∫ψ* Â ψ) then the negative values for ψ present no difficulty at all.
See these videos for some additional detail:
probability: ua-cam.com/video/Sk3VPtV5bQI/v-deo.html
expectation values: ua-cam.com/video/ogscPg1FncI/v-deo.html
If you repeat the examples in those videos with a negative function ψ(x), then everything still works out fine.