Hi Natalie! Here are my answers to these questions. The general technique to complete the square is always the same.

Factor out the coefficient of x2 (if it is not already 1), then introduce a constant equal to the square of half the coefficient of x, then return it. This introduction of constant is needed to complete the perfect square.

The general method of finding out the coordinates of the turning point is also always the same. To sketch the graph, we need to know three things.

The shape of graph (“smiley face” or “sad face”), the coordinates of the turning point and the coordinates of the y-intercept (the coordinates of the x-coordinates are not required to sketch the graph).

Where necessary (only when asked), we find the x-intercepts by factorisation or by usage of the quadratic formula.

This topic is also seen in a Maths so you must be able to master the technique of completing the square.

Let me know if you do not understand my workings and I will do my best to explain the concept again.