Difference between revisions of "2020 USOJMO Problems/Problem 6"
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Let <math>n \geq 2</math> be an integer. Let <math>P(x_1, x_2, \ldots, x_n)</math> be a nonconstant <math>n</math>-variable polynomial with real coefficients. Assume that whenever <math>r_1, r_2, \ldots , r_n</math> are real numbers, at least two of which are equal, we have <math>P(r_1, r_2, \ldots , r_n) = 0</math>. Prove that <math>P(x_1, x_2, \ldots, x_n)</math> cannot be written as the sum of fewer than <math>n!</math> monomials. (A monomial is a polynomial of the form <math>cx^{d_1}_1 x^{d_2}_2\ldots x^{d_n}_n</math>, where <math>c</math> is a nonzero real number and <math>d_1</math>, <math>d_2</math>, <math>\ldots</math>, <math>d_n</math> are nonnegative integers.) | Let <math>n \geq 2</math> be an integer. Let <math>P(x_1, x_2, \ldots, x_n)</math> be a nonconstant <math>n</math>-variable polynomial with real coefficients. Assume that whenever <math>r_1, r_2, \ldots , r_n</math> are real numbers, at least two of which are equal, we have <math>P(r_1, r_2, \ldots , r_n) = 0</math>. Prove that <math>P(x_1, x_2, \ldots, x_n)</math> cannot be written as the sum of fewer than <math>n!</math> monomials. (A monomial is a polynomial of the form <math>cx^{d_1}_1 x^{d_2}_2\ldots x^{d_n}_n</math>, where <math>c</math> is a nonzero real number and <math>d_1</math>, <math>d_2</math>, <math>\ldots</math>, <math>d_n</math> are nonnegative integers.) | ||
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+ | ==See Also== | ||
+ | {{USAJMO newbox|year=2020|num-b=5|after=Last Problem}} | ||
+ | {{MAA Notice}} |
Latest revision as of 18:16, 6 October 2023
Problem
Let be an integer. Let be a nonconstant -variable polynomial with real coefficients. Assume that whenever are real numbers, at least two of which are equal, we have . Prove that cannot be written as the sum of fewer than monomials. (A monomial is a polynomial of the form , where is a nonzero real number and , , , are nonnegative integers.)
See Also
2020 USAJMO (Problems • Resources) | ||
Preceded by Problem 5 |
Followed by Last Problem | |
1 • 2 • 3 • 4 • 5 • 6 | ||
All USAJMO Problems and Solutions |
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