We reviewed the key features of parabolas today, but this time from an algebraic perspective. We’ve already seen that the roots of the parabola (aka the *x*-intercepts or the zeroes) are the solutions we get from the quadratic equation. We saw today that the equation for the Axis of Symmetry can be obtained from the standard form of a quadratic equation using the formula *x* = –*b*/(2*a*). And since the vertex is on the axis of symmetry, the *x-*coordinate of the vertex is that same value (and the *y*-value is obtained by plugging that *x*-value into the equation).

## Today’s Files

- HW 3.16 – Identifying Key Features Algebraically
- Lesson Video (finding axis of symmetry algebraically)
- Video Archive

## Cumulative IXL Modules

- J.4 Solve a quadratic equation using square roots
- J.5 Solve a quadratic equation using the zero product property
- J.6 Solve a quadratic equation by factoring
- J.9 Solve a quadratic equation using the quadratic formula
- L.1 Roots of integers
- L.3 Find roots using a calculator
- L.7 Multiply radical expressions
- T.1 Identify the direction a parabola opens
- T.2 Find the vertex of a parabola
- T.4 Find the axis of symmetry of a parabola
- From Algebra 1