Calculus Help

[Blackcat47]

I am new to this site, I am trying to offer some support to my Niece for her college work but it has been some time since I was at Uni, so Im struggling as to where to start and I would appreciate your help.

Question 1

The Decay of voltage, v, volts across a capacitor at time t seconds is given by v = 250e ^-t/3.

i) Show the natural decay curve over the first six seconds and determine the change in voltage with respect to time (dv/dt) from your graph at t = 3 seconds.
ii) Compare the results from your graph with those using calculus methods.

 

[JeffM]

I am new to this site, I am trying to offer some support to my Niece for her college work but it has been some time since I was at Uni, so Im struggling as to where to start and I would appreciate your help.

Question 1

The Decay of voltage, v, volts across a capacitor at time t seconds is given by v = 250e ^-t/3.

i) Show the natural decay curve over the first six seconds and determine the change in voltage with respect to time (dv/dt) from your graph at t = 3 seconds.
ii) Compare the results from your graph with those using calculus methods.

Blackcat

We have found that it works much better to deal with students directly. If you want to look over your niece's shoulder while she works with us, that is excellent. Please read READ BEFORE POSTING to learn how we provide help and what we expect from students.

A large part of the problem given above requires that the student first graph the indicated function. Has that been done? The next step is to graph an ESTIMATED tangent line at t = 3. Has that been done? Does your niece remember from beginning algebra how to compute the slope of a straight line? It is very hard to help if we do not know what has already been done (if anything) or what the difficulty is in proceeding (or even starting). In this case, I have indicated what needs to be done to start the problem.

Trying to determine what a student's difficulty is, whether conceptual or mechanical, and then helping the student resolve that specific difficulty is what we try to do. As I said above, it is very hard (indeed virtually impossible) to do that successfully without talking to the student directly.