MATH 246 Midterm: MATH246H OSBORN-J FALL2004 0101 MID EXAM

• School: University of Maryland
• Department: Mathematics
• Course: MATH 246
• Professor: All

Document Summary

Show your work and state your answers clearly and concisely. No calculators: determine whether or not each of the following equations is exact; if exact, nd the solution: (a) (3 + yexy)dx + (xexy. 4)dy = 0 (b) (ey + 2xy)dx + (xey. Yex)dy = 0. (c) (x3 + y3)dx + 3xy2dy = 0: at time t=0 a tank contains 25 lbs of salt dissolved in 800 gals of water. Graph the solutions of this equation by the qualitative method, identifying any equilibrium solutions, and indicating whether they are unstable or asymptotically stable. Are these results compati- ble with your conclusion in (b)ii: consider the di erential equation dy dt. 4. (a) solve the initial value problem y = 4 y(1) = 0. (b) consider the di erential equation dy dx. 2xy x2 + 1: show that it is linear, separable, and exact, olve.