2. A person was given the following question. They were told that t = cos(r) – rand that r = T. t=\cos (r)-r \quad r=\pi They were then asked to

find the value of t. They proceeded as follows t=\cos (r)-r =\cos (\pi)-\pi =-1-\pi (a) What action did they perform to get from line 1 to line 2? (b) What allowed them to perform that action?