The problem provides an incomplete table of values for the function $y = x(x-2)-3$. We need to: (i) Find the value of $y$ when $x=2$. (ii) Draw the graph of the function using a suitable scale on a standard coordinate plane. (iii) Write down the coordinates of the turning point of the graph. (iv) Find the roots of the equation $x^2 - 2x - 3 = 0$ using the graph. (v) Describe the behavior of $y$ when $-1 \le x \le 1$.
2025/6/23
1. Problem Description
The problem provides an incomplete table of values for the function . We need to:
(i) Find the value of when .
(ii) Draw the graph of the function using a suitable scale on a standard coordinate plane.
(iii) Write down the coordinates of the turning point of the graph.
(iv) Find the roots of the equation using the graph.
(v) Describe the behavior of when .
2. Solution Steps
(i) Find the value of when .
We have the function .
Substitute into the equation:
(ii) Draw the graph of the function.
We complete the table using :
When ,
When ,
When ,
When ,
When ,
When ,
When ,
The completed table is:
x | -2 | -1 | 0 | 1 | 2 | 3 | 4
--|----|----|----|----|----|---|---
y | 5 | 0 | -3 | -4 | -3 | 0 | 5
We would then plot these points on a coordinate plane and draw a smooth curve through them. (Since I cannot draw a graph here, imagine plotting the points and connecting them with a curve. The graph is a parabola.)
(iii) Coordinates of the turning point.
From the completed table or the equation, we can see that the turning point (vertex) of the parabola is at .
(iv) Roots of the equation .
The roots of the equation are the x-values where the graph intersects the x-axis, i.e., where .
From the graph (or the table), we can see that the graph intersects the x-axis at and . Therefore, the roots are and .
(v) Behavior of when .
When , the y-values decrease from to . So, is decreasing.
3. Final Answer
(i) When , .
(ii) Graph: (Cannot draw the graph here)
(iii) Turning point:
(iv) Roots: and
(v) When , is decreasing.