Question

A diver dives from the board at a local swimming pool. Her height, y, in metres, above the water in terms of her horizontal distance, x, in metres, from the end of the board is given by y= -x^2 + 2x + 3. What is the diver's maximum height?

Answer 1

Answer:

4 meters

Step-by-step explanation:

Given a quadratic equation in which the coefficient of $x^2$ is negative, the parabola opens up and has a maximum point. This maximum point occurs at the line of symmetry.

Since the divers height, y is modeled by the equation

$y= -x^2 + 2x + 3$

Step 1: Determine the equation of symmetry

In the equation above, a=-1, b=2, c=3

Equation of symmetry, $x=-\dfrac{b}{2a}$

$x=-\dfrac{2}{2*-1}\\x=1$

Step 2: Find the value of y at the point of symmetry

That is, we substitute x obtained above into the y and solve.

$y(1)= -1^2 + 2(1) + 3=-1+2+3=4m$

The maximum height of the diver is therefore 4 meters.