Exam-style question
Try this first
Which check prevents an error when rewriting a fractional power as a root?.
- A.B1: check notation, restrictions and final form
- B.Use any familiar GCSE calculation even if it ignores the laws of indices for all rational exponents
- C.Write only the final answer without showing the mathematical method
- D.Change the notation or restrictions to make the algebra look simpler
Model answer
What a good answer should say
- The correct answer is B1: check notation, restrictions and final form.
- It is correct because a fractional exponent represents a root and a power, so the final expression must preserve the order and any domain restrictions.
This answer is tied to the objective: B1 Understand and use the laws of indices for all rational exponents..
Explanation
Why this works
Use the explanation to connect the worked answer back to B1 Understand and use the laws of indices for all rational exponents..
This B1 item targets rational exponents. A fractional power such as x^(m/n) must be interpreted as an nth root combined with a power, and restrictions may matter when even roots are involved.
The distractors ignore notation or treat the exponent as an ordinary integer.
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.