The current, $i$, through a circuit is given by
$$
i=5 t e^{-5 t} \quad t \geq 0
$$
I What is the value of $i$ for large $t$, $t \rightarrow \infty ?$
ii Find the maximum current through the circuit.
iii Sketch the graph of $i$ against $t$ for $t \geq 0$