Mathematics

Mathematics

Problem

The polynomial x2+px+12x^2 + px + 12 has two distinct positive zeros in the ratio 1:31:3. Find the value of pp. a) 88 b) −12-12 c) −8-8 d) −16-16
Intuitive explanation

The key is to use the ratio between the roots to express them in terms of a single variable, then apply Vieta's formulas. If the roots are in ratio 1:31:3, call them rr and 3r3r where r>0r > 0. Their product gives you rr directly, and their sum gives you pp—but remember that pp is the negative of the sum of roots for a monic quadratic.

Intuitive explanation

The key is to use the ratio between the roots to express them in terms of a single variable, then apply Vieta's formulas. If the roots are in ratio 1:31:3, call them rr and 3r3r where r>0r > 0. Their product gives you rr directly, and their sum gives you pp—but remember that pp is the negative of the sum of roots for a monic quadratic.

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