I'm stuck on this one:

$\displaystyle \text{Compute } \lim_{u \rightarrow 1 } \frac{u^4-1}{u^3-1}$

$\displaystyle = \frac{1^4-1}{1^3-1}$

$\displaystyle = \frac{0}{0 } \text{Indeterminate}$

$\displaystyle \lim_{u \rightarrow 1 } \frac{u^4-1}{u^3-1}$

$\displaystyle = \lim_{u \rightarrow 1 } \frac{(u-1)(u+1)(u-1)(u-1)}{(u-1)(u+1)(u+1)}$

$\displaystyle = \lim_{u \rightarrow 1 } \frac{(u-1)(u-1)}{(u+1)}$

$\displaystyle = \frac{(1-1)(1-1)}{(1+1) }$

$\displaystyle = \frac{0}{2}$