Day 78 Study Record: Advanced Mathematics: Differential Equations (Song Hao writing on the blackboard)

Differential equation is a mathematical language that describes the relationship between variables in natural phenomena. It is an equation based on mathematical concepts such as functions, derivatives, and differentials, and reveals the inherent relationship between variables in natural phenomena. Differential equations are widely used in various fields such as physics, engineering, biology, economics, and statistics.

Differential equations can be divided into first-order differential equations and higher-order differential equations. First order differential equations involve first derivatives of variables while higher order differential equations involve higher order derivatives of variables. Depending on the characteristics of the differential equation, different methods can be used to solve it.

Some basic methods for solving differential equations include:

  1. Separation of Variables: Turn the differential equation into a function of two variables, and then integrate them separately.

  2. Homogeneous differential equation method: For a certain type of differential equation, find a special substitution method to make the equation into a form of separable variables.

  3. First-order linear differential equation method: convert the differential equation into a first-order linear differential equation, and then apply the solution of the linear differential equation.

  4. Constant coefficient linear differential equation method: For a special type of first-order/second-order differential equation, find the general solution of the linear combination of the three possible solutions of the equation.

  5. Dynamics method: convert differential equations into dynamical systems, and study the behavior and stability of differential equations through numerical simulation and other methods.

Differential equations have a wide range of applications, such as:

  1. In physics, differential equations can be used to describe physical laws, such as kinematics, mechanics, thermodynamics, quantum mechanics and other fields.

  2. In engineering, differential equations can be used to solve control problems, circuit analysis, elastic mechanics, etc.

  3. In biology, differential equations can be used to study biological evolution, population growth, biological genetics and other issues.

  4. In finance, differential equations can be used to describe stock price changes, option pricing, risk management and other issues.

Therefore, differential equations are an indispensable mathematical foundation in natural science and social science research.

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separable variable

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homogeneous equation

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First Order Linear Differential Equations

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Bernoulli equation

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Reducible Higher Order Differential Equations

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Homogeneous Linear Differential Equations with Constant Coefficients

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So far, the content of high mathematics is over. But it's been two weeks. If this goes on, wait until you learn to play all advanced mathematics, linear algebra, probability theory and discrete mathematics.
Therefore, it was decided to start from the back, and the mathematical foundation and C++ were carried out simultaneously.

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Origin blog.csdn.net/weixin_45694614/article/details/131265725