Robin bought a computer for $1,250. It will depreciate, or decrease in value, by 10% each year that she owns it.
Write an explicit formula to represent the sequence.

Question

Robin bought a computer for $1,250. It will depreciate, or decrease in value, by 10% each year that she owns it. 
Write an explicit formula to represent the sequence.

anonymous · Answer

@whpalmer4

anonymous · Answer

V = P(1-R)^n

V= future value, P= present value, R= depreciation rate, and n= # of years.

johnweldon1993 · Answer

so it would be 1250(1-r)^n where n is number of years

johnweldon1993 · Answer

in this case it'd be 1250(.90)^n

anonymous · Answer

oh! so it's .90 instead of .10 because it's a decreasing value?

johnweldon1993 · Answer

you well remember it's exponential decay....so its 1-r...the r is 10%...so 1-10% is .90

anonymous · Answer

or is that just the 1-r thing? I'm sorry, I'm confused. :P

anonymous · Answer

oh, okay. gotcha.

johnweldon1993 · Answer

.90 is 1 - r yes....but thats only for exponential decay...if it was exponential growth...it would be 1+r

anonymous · Answer

oh! Okay! I think that's why my other formula was failing. SO the next part of the question is to find the value at the beginning of the 6th year. So I would write this? |dw:1362776535373:dw|