Stage 11 · Quadratic Equations
11.5.3 Evaluating Symmetric Expressions in the Roots
11.5 The Relationship Between Roots and Coefficients (Vieta's Formulas)
Point 3 of 4
11.5.3 Evaluating Symmetric Expressions in the Roots
Core ideaExpressions like x₁²+x₂² or 1/x₁+1/x₂ can all be built from the two building blocks of sum and product.
Module goal. Read off the sum and product of the two roots without solving, then work backwards to build an equation from its roots and evaluate symmetric expressions.