There is an identity symmetry (rotation by 0 degrees) that acts just as the number zero acts in our number system. And every symmetry can be undone, just as adding 3 can be undone by adding –3: For ...

Revise how to identify the y-intercept, turning point and axis of symmetry of a quadratic function. BBC Bitesize Scotland revision for SQA National 5 Maths.

This also gives the equation of the line of symmetry for the quadratic graph. The value of \(y\) when \(x = 3\) is -5. This value is always the same as the constant term in the completed square ...