Example 7

Solution:

When we plot these points and join them with a smooth curve, we
obtain the following graph.

Note:
The graph is a parabola
which opens upwards. Clearly, the graph
is symmetrical about the
line x = 1. Therefore, the equation of
the axis of symmetry is x = 1.
The minimum value of y is 0 and it occurs when x = 1.
The vertex of the parabola is the point (1, 0).
In general:

In the example above, a = 1 and b = 1. |