Polynomials
The discriminant

Polynomials

Quadratics​

• Factorising by sum and product {part 1}
• Factorising by sum and product {part 2}
• Factorising by cross method {part 1}
• Factorising by cross method {part 2}
• Solving quadratics: by factorisation
• Solving quadratics: by completing the square
• Solving quadratics: the quadratic formula
• The discriminant
• Sketching quadratics from factorised form
• Sketching quadratics from vertex form {part 1}
• Sketching quadratics from vertex form {part 2}
• Sketching quadratics by completing the square
• Sketching quadratics from general form
• Finding the quadratic function from its graph {part 1}
• Finding the quadratic function from its graph {part 2}
• Finding the quadratic function from its graph {part 3}
• Finding where functions meet

Student Questions

• Sketching quadratics by completing the square
• Where functions meet​

Cubics and Quartics

• Polynomial equality (equating coefficients)
• Factorising cubic polynomials
• Solving cubic polynomials
• Sketching cubic functions
• Finding cubic functions from its graph
• Sketching quartic functions
• ​Finding quartic functions from its graph​

It is possible to determine how many solutions a quadratic equation has without actually solving the entire equation. In the quadratic formula, what is under the square root is referred to as the discriminant (referred to by the symbol delta) and can be used to determine how many solutions a quadratic has.
\[\Delta =b^{2}-4ac\]