Plot quadratic graphs from a table, read roots and turning points off them, sketch from factors and solve inequalities.
What you will learn
- Plot a quadratic from a table of values
- Read roots, intercepts and the turning point
- Solve a quadratic inequality
From table to curve
Substitute each x into the equation.
Brackets stop the classic slip with negatives: (−2)² = 4, not −4.
This is y = x² − 2x − 3. Join the points with a smooth curve: a U shape (the x² term is positive), with no flat bottom and no straight bits.
The rest of this lesson and its 8 practice questions are locked.
In this lesson
- From table to curve
- What you can read off
- Inequalities (Higher)
- Try it: Move the curve
8 practice questions, marked as you go; about 25 minutes in all.
Key terms
Below
In this unit: Quadratics
Expand and factorise quadratics, solve them by factorising, the formula and completing the square, and read roots and turning points from graphs.