Question

工數白癡

正合方程式的問題（工數）
有點毫無頭緒😵‍💫
求解

Section 1.3 Problems
測試是否為正合
In each of Problems 1-5, test the differential equation
for exactness. If it is exact in some region R of the plane,
find a potential function and a general solution, perhaps
implicitly defined, that is valid for that region. If it is not
exact on any region, do not attempt a solution.
1. 2y² + yexy + (4xy + xexy + 2y)y' = 0
2. 4xy + 2x + (2x² + 3y²)y' = 0
3. 4xy + 2x²y + (2x² + 3y²)y' = 0
4.2 cos(x+y) - 2x sin(x + y) - 2x sin(x + y)y' = 0
tlsx9
² +y+ (3y² + x)y' = 0
5.

正合方程式 工程數學