The coordinates of the turning point (maximum) is (9/2, 25/4).
How to find the turning point
The symmetry of a quadratic function is given by the axis of symmetry, which is a vertical line that passes through the vertex (turning point) of the parabola.
The formula for the axis of symmetry is given by:
x = -b / 2a
where b = 9 and a = -1
x = -9 / (2 * -1) = 9/2
Calculate the value of y
y = (9/2)² + 9(9/2) -14
y = 25/4
The coordinates of the turning point (maximum) are
(9/2, 25/4).