Hi:

This is not really so urgent, but I couldn't find anywhere that exponential questions seem to go. Any tips?

Question is to solve the following:

The current, i amps, flowing through an electrical circuit at time t seconds is known to be decreasing according to the equation

i=Ie^(-5t)

where I 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.

hmmm!

current is decreasing from 2 to 0.5. So, it has decreased by 1.5.

Do I start here by - Ie^(-5t) becomes -5tIe - like in the basic logarithm rule

loga^n = nloga

If the initial current is 2, does this then become -5t2e?

I think I'm lost already