Consider the linear function y = ,3.) + [31.13 + u The derivative of a function describes the change in y given a small change in I. In the case of the linear function 3!; EZl Replacing the 8 with t, this says that by : lm, so for example with a change in 3 of2, the change in y is Ag : ,81 - 2. a. Use the same logic to show that if y = ,3.) + 131 ]J:i($] + u, then by = le'z, where %m : %_ (Hint: you need to use the fact that alumnae = 1/3, then replace with t and then do some algebra.) Solution: b. Let voteA he the fraction oTthe vote received by candidate A. Also let empendA denote the total campaign expenditures of candidate A in 51,0005. Suppose the vote share for candidate A is determined by voter! = 45+ln{empendA] +1.5 If the candidate increases expenditures by 10% what will he the approximate change in the vote share