Depreciation/Rate of Change (Calculus I)
Problem: The value of a piece of machinery depreciates exponentially. When purchased new, it was worth $70,000. After 4 years, it was worth $55,200. Find the rate of change of the value of the equipment after 4 years.
I started with:
4r = ln (55,200/70,000)
4r = -0.2375322...
divide by 4 on both sides..
r = -.05938...
multiply by initial value (70000)
which was not an answer choice, lol
I'm obviously setting this up wrong, any help is appreciated :D