Introduction:
When practicing numerical problems in electrical engineering, there is a debate on whether to use formula sheets or derive formulas on our own. Both approaches have their advantages and disadvantages, and the choice ultimately depends on the individual's learning style and the specific problem at hand.

Using Formula Sheets:
Using formula sheets can be a time-saving approach, especially when dealing with complex problems that require multiple formulas. Here are some advantages of using formula sheets:

1. Efficiency: Formula sheets provide a quick reference to the necessary formulas, allowing for faster problem-solving.
2. Accuracy: By using established formulas, there is a reduced chance of making errors during the derivation process.
3. Focus on Problem-Solving: With pre-determined formulas, the focus can be solely on understanding and solving the numerical problem itself.

However, there are some limitations to relying solely on formula sheets:

1. Lack of Understanding: Using formula sheets without understanding the derivation can hinder deep comprehension of the underlying concepts.
2. Limited Application: Formula sheets may not cover all possible scenarios, and the derived formulas might be more versatile in practice.
3. Dependency: Relying solely on formula sheets can create a dependency on memorization rather than developing problem-solving skills.

Deriving Formulas on Own:
Deriving formulas on our own can be a valuable learning experience, especially for foundational concepts in electrical engineering. Here are some advantages of deriving formulas:

1. Deep Comprehension: Deriving formulas helps in understanding the underlying principles and concepts, leading to a deeper comprehension of the subject.
2. Flexibility: Deriving formulas allows for customization and adaptation to different scenarios, enhancing problem-solving skills.
3. Application in Real-Life Situations: Deriving formulas helps in developing the ability to apply theoretical knowledge to practical electrical engineering problems.

However, there are some drawbacks to deriving formulas on our own:

1. Time-Consuming: Deriving formulas can be time-consuming, especially for complex problems, and may not be feasible in time-limited situations.
2. Potential for Errors: The process of deriving formulas involves multiple steps, increasing the chances of making errors, which can lead to incorrect results.
3. Need for Strong Mathematical Background: Deriving formulas requires a strong understanding of mathematical concepts and techniques, which may be challenging for some students.

Conclusion:
In conclusion, both using formula sheets and deriving formulas on our own have their merits and drawbacks. It is recommended to strike a balance between the two approaches by initially understanding the derivation process and then utilizing formula sheets for efficiency and accuracy. This allows for a deeper understanding of the subject while also ensuring timely and accurate problem-solving. Ultimately, the choice between the two approaches should be based on the specific problem, time constraints, and individual learning preferences.