Engineering Solving for i and v_x: A Homework Challenge

[SuperCat]

Homework Statement

Find i and v_x

Given answer:

2. Homework Equations 3. The Attempt at a Solution
I have attempted the problem in two different manners, and I consistently reach a different answer. I would appreciate if someone would be willing to take the time to attempt the problem and confirm whether the provided solution is correct.

My answer:
i(t) = 5* e^(-5.6*t)
I have not attempted to solve for v_x yet, because I want to verify the first part of the answer.

Method 1: Apply KVL directly to the circuit

Method 2: Find the equivalent resistance at the inductor terminals with a test voltage source.
I am not showing the work for this method, but I did it this way as well and received the same answer as my first attempt.

If my attempt is wrong, I really would appreciate some insight into where I went wrong.

 

[gneill]

I think your result looks better than theirs! Considering that they used the unit V for both voltage and current in their answer, I suspect that they have an editing issue with the answer key.

 

[SuperCat]

Good point, I completely managed to overlook that! I just couldn't find this listed in the errata for my book so I blindly trusted it.