The current, amps, flowing through an electrical circuit at time seconds
is known to be decreasing according to the equation .
where is the current initially flowing.
Given that the initial current in this circuit is 2 amps,
calculate how long it takes for the current to decrease to 0.5 amps,
giving your answer in seconds correct to 2 d.p.
We are told the initial current is 2 amps.
. . So the function is: .
We are asked: When is ?
We have: .
Therefore: . seconds.