Example 1 — Find the roots fast
EasyProblem
Where does cross the -axis?
Solution
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Standard form hides the roots; a different representation would expose them.
Name the structure before touching arithmetic — that is what makes the right method obvious.
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Ask the recognition question: Could a different representation of this same object make the feature I need obvious?
If the answer is yes, the concept applies; the cue, not a keyword, decides the method.
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Switch viewpoints by factoring into a form where roots are visible.
The rule is chosen only after the structure matches, so the steps mean something.
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, which is zero at and .
Keep units, shape, or answer form tied to the story so the work does not become symbol pushing.
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Check the answer against the original question.
It should fit the mental model — turn the object until a new face shows. If it does not, revisit the recognition step before changing the arithmetic.
Answer
and
Takeaway: Changing representation of the same object made the answer obvious.