课程名称︰工程数学
课程性质︰必修
课程教师︰萧浩明
开课学院：工学院
开课系所︰机械系
考试日期（年月日）︰2016/10/12
考试时限（分钟）：70
试题 :
1. (20%) (4e^(-y)sinx-1)dx-dy=0
2. (20%) (ycosx+2xe^y)dx+(sinx+(x^2)e^y+2)dy=0 is exact. Find its general
solution ψ by (1) standard method, (2) express the left side in a total
differential form and then integrate both sides to obtain the solution ψ.
3. (20%) (y+xy^2)dx+(x-x^2y)dy=0
4. (20%) y'=(2xy)/(x^2+y^2-1)
5. (20%) (x-lny)dy+ylnydx=0