Exam-style question
Try this first
For constructing a differential equation in context, which statement shows the best modelling step?.
- A.Define the variables and translate the stated rate relationship into an equation involving a derivative.
- B.Solve a quadratic equation because every model must be algebraic.
- C.Differentiate a random expression before reading the context.
- D.Remove units and variables so the equation is shorter.
Model answer
What a good answer should say
- The correct answer is Define the variables and translate the stated rate relationship into an equation involving a derivative.
- This is the best choice because it names the A-level method being tested and explains the mathematical check needed for this objective.
This answer is tied to the objective: G6 Construct simple differential equations in pure mathematics and in context, including contexts such as kinematics, population growth and modelling the relationship between price and demand..
Explanation
Why this works
Use the explanation to connect the worked answer back to G6 Construct simple differential equations in pure mathematics and in context, including contexts such as kinematics, population growth and modelling the relationship between price and demand..
Define the variables and translate the stated rate relationship into an equation involving a derivative. is correct.
It is specific to the learning objective, keeps the method visible, and avoids the generic shortcut described by the distractors.
Maths method check
- Topic focus: Pure Mathematics.
- Question style: practice.
- Reasoning demand: application.
- Check the operation, notation, units, and final answer form against the question before moving on.
Common mistake
No common mistake is linked to this question yet.