hokhani
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- TL;DR Summary
- Do differential operators change corresponding to their variables' signs?
Consider the operator ##\hat{A} (x,t) =\frac{d}{dx} +f(x,t)## where ##\hat{A}## is an operator and ##f(x,t)## a function. I don't know which of the following expression is correct for ##\hat{A} (-x,-t)##?
first one: $$\hat{A} (-x,-t) =\frac{d}{dx} +f(-x,-t)$$ and the second: $$\hat{A} (-x,-t) =-\frac{d}{dx} +f(-x,-t)$$
first one: $$\hat{A} (-x,-t) =\frac{d}{dx} +f(-x,-t)$$ and the second: $$\hat{A} (-x,-t) =-\frac{d}{dx} +f(-x,-t)$$