• explain what an integrating factor is and why introducing one makes solving a linear, first-order rate equation possible. (An "explanation" that consists only of formulas for integrating factors and the solutions will receive no marks.)
• Determine the appropriate integrating factor for the rate equation
• (1)^3 / +4(1)^2 y = e^t

• do NOT need to solve the equation, just determine the integrating factor. Make sure to provide enough detail to demonstrate how you arrived at your integrating factor.
• REMINDER: not permitted to use any kind of technology,whether on- or off-line, to assist with any part of this calculation except simple arithmetic.