Function:
\[ f(x) = \begin{cases} \dfrac{x}{e^{\pi x} - 1}, & x \neq 0 \\ \dfrac{1}{\pi}, & x = 0 \end{cases} \]
\[ \lim_{x \to 0} f(x) = \frac{1}{\pi} = f(0) \quad \Rightarrow \quad \text{Function is continuous at } x = 0 \]
\[ f'(0) = \lim_{h \to 0} \frac{f(h) - f(0)}{h} = -\frac{1}{2} \]
$f'(0)=\lim_{x\to0}\dfrac{f(x)-f(0)}{x}$
$=\lim_{x\to0}\dfrac{x^2\sin(1/x)}{x}$
$=\lim_{x\to0}x\sin(\frac{1}{x})=0$
For $x\ne0$,
$f'(x)=2x\sin\left(\dfrac{1}{x}\right)-\cos\left(\dfrac{1}{x}\right)$
Answer: $\boxed{f'(0)=0}$ ✅
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