Chapter 11

Find \(\cos ^{-1}\left[\cos \left(-\frac{\pi}{6}\right)\right]\)

In \(2005,\) a small business purchased a copier for \(\$ 4500 .\) By \(2008,\) the value of the copier had decreased to \(\$ 3300 .\) Assuming the depreciation is linear, (a) find the rate-of-change \(m=\frac{\Delta \text { value }}{\Delta \text { time }}\) and discuss its meaning in this context. (b) Find the depreciation equation and (c) use the equation to predict the copier's value in 2012 . (d) If the copier is traded in for a new model when its value is less than \(\$ 700\), how long will the company use this copier?