1. The user has input the expression $\frac{d}{dx}$ which signifies the derivative operator with respect to $x$. 2. This expression alone is not a complete problem but indicates differentiation, which means finding the rate of change or slope of a function. 3. To proceed, we need a function $f(x)$ to apply this derivative operator and find $\frac{df}{dx}$. 4. For example, if $f(x) = x^2$, then applying $\frac{d}{dx}$ gives $\frac{d}{dx} x^2 = 2x$. 5. Please provide a function to differentiate, or specify the problem involving $\frac{d}{dx}$ so I can assist further.