1. Physics: Calculus can be used to calculate the relationship between speed, acceleration and force, analyze the equation of motion, and study the motion and mechanical properties of objects. Calculus can also be used to analyze problems in electromagnetic fields, fluid mechanics, thermodynamics and other fields.
2. Economic finance: in economic finance, it is used to analyze the relationship between economic variables, calculate marginal effects and optimize problems. For example, calculus can be used to determine the marginal product of the production function, calculate the marginal cost of the cost function, and solve the optimal portfolio problem.
3. Engineering: It is widely used in engineering. For example, in the fields of mechanics, structural engineering, fluid mechanics and so on.
4. Computer science: used in machine learning, artificial intelligence and other fields.
5. Other fields: used in biology, medicine, geography and other fields.