Before generation
Use when learners confuse degree with term count, overlook a missing power, misread a negative leading coefficient, or treat zero constant as absent from the coefficient vector. The diagnostic reads already collected standard-form coefficients. It does not combine like terms, parse symbolic expressions, classify end behavior, find zeros, factor, differentiate, or define a degree for the zero polynomial.
Worked example
The vector 2, 0, negative 3, 5 represents a cubic with leading coefficient two, constant five, and three nonzero terms. Negative 1, 4, 0 is quadratic with zero constant. A single seven is degree zero. The final vector has four entries and therefore degree three, so its learner degree two is flagged despite the other structure claims.
Formula or methodology
For a nonzero descending coefficient vector of length n plus one, degree equals n, leading coefficient is the first value, constant is the last value, and term count is the number of nonzero coefficients. Internal zero entries preserve missing powers and must not be deleted before degree positions are assigned.
How to interpret the result
Supported means all four structure claims agree with the supplied vector. A degree conflict with correct leading and constant values often reveals a missing-zero or term-count misconception. Review standard form, like-term collection, exponent order, coefficient signs, zero coefficients, equivalent symbolic forms, and the special status of the zero polynomial.
Common mistakes
Do not count terms to determine degree, discard an internal zero and shift all later powers, use the largest coefficient as degree, call the first exponent a coefficient, overlook a zero constant, or assign the zero polynomial an ordinary degree. Write every descending power position, including zero placeholders, before naming structure.