We are given the limit:
\[ \lim_{t \to 0} \frac{\sin(2t)}{8t^2 + 4t} \]
We can simplify the expression:
\[ \frac{\sin(2t)}{8t^2 + 4t} = \frac{\sin(2t)}{4t(2t + 1)} \]
As \( t \to 0 \), \( \sin(2t) \approx 2t \), so:
\[ \frac{\sin(2t)}{4t(2t + 1)} \approx \frac{2t}{4t(2t + 1)} = \frac{2}{4(2t + 1)} \]
Now, taking the limit as \( t \to 0 \), we get:
\[ \lim_{t \to 0} \frac{2}{4(2t + 1)} = \frac{2}{4(0 + 1)} = \frac{2}{4} = \frac{1}{2} \]
Answer: \( \frac{1}{2} \)
If $\lim_{x \to 1} \frac{(x-1)(6+\lambda \cos(x-1)) + \mu \sin(1-x)}{(x-1)^3} = -1$, where $\lambda, \mu \in \mathbb{R}$, then $\lambda + \mu$ is equal to