Plagiarism - bachelor thesis
If I understand correctly, you state and cite formulas, then derive a further formula. Presumably, the derivation isn't new, and you are concerned that you didn't provide a source for the derivation. Given that you consider the further formula to be well-known, it perhaps doesn't matter so much. Nonetheless, to protect yourself, you could email your examiners and explain that you inadvertently forgot to mention that the derivation is not your own, it is a well-known result, perhaps providing a citation.