CARA: vNM utility with constant absolute risk aversion
This is a classic graduate/advanced undergraduate level problem in microeconomics/finance. It asks to find out utility function that corresponds to a constant Arrow-Pratt measure of absolute risk-aversion.
Here's a problem from Mas-Colell, Whinston and Green textbook on Microeconomic Theory:
Given that the Arrow-Pratt measure of absolute risk-aversion is a constant, derive the corresponding form of the von Neumann-Morgenstern utility function.