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 $-1 \le x \le 1$.

AlgebraQuadratic FunctionsGraphingParabolaRootsVertex
2025/6/23

1. Problem Description

The problem provides an incomplete table of values for the function y=x(x2)3y = x(x-2)-3. We need to:
(i) Find the value of yy when x=2x=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 x22x3=0x^2 - 2x - 3 = 0 using the graph.
(v) Describe the behavior of yy when 1x1-1 \le x \le 1.

2. Solution Steps

(i) Find the value of yy when x=2x=2.
We have the function y=x(x2)3y = x(x-2) - 3.
Substitute x=2x=2 into the equation:
y=2(22)3=2(0)3=03=3y = 2(2-2) - 3 = 2(0) - 3 = 0 - 3 = -3
(ii) Draw the graph of the function.
We complete the table using y=x(x2)3=x22x3y = x(x-2)-3 = x^2-2x-3:
When x=2x=-2, y=(2)22(2)3=4+43=5y = (-2)^2 - 2(-2) - 3 = 4 + 4 - 3 = 5
When x=1x=-1, y=(1)22(1)3=1+23=0y = (-1)^2 - 2(-1) - 3 = 1 + 2 - 3 = 0
When x=0x=0, y=(0)22(0)3=003=3y = (0)^2 - 2(0) - 3 = 0 - 0 - 3 = -3
When x=1x=1, y=(1)22(1)3=123=4y = (1)^2 - 2(1) - 3 = 1 - 2 - 3 = -4
When x=2x=2, y=(2)22(2)3=443=3y = (2)^2 - 2(2) - 3 = 4 - 4 - 3 = -3
When x=3x=3, y=(3)22(3)3=963=0y = (3)^2 - 2(3) - 3 = 9 - 6 - 3 = 0
When x=4x=4, y=(4)22(4)3=1683=5y = (4)^2 - 2(4) - 3 = 16 - 8 - 3 = 5
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 (1,4)(1, -4).
(iv) Roots of the equation x22x3=0x^2 - 2x - 3 = 0.
The roots of the equation are the x-values where the graph intersects the x-axis, i.e., where y=0y=0.
From the graph (or the table), we can see that the graph intersects the x-axis at x=1x=-1 and x=3x=3. Therefore, the roots are x=1x=-1 and x=3x=3.
(v) Behavior of yy when 1x1-1 \le x \le 1.
When 1x1-1 \le x \le 1, the y-values decrease from 00 to 4-4. So, yy is decreasing.

3. Final Answer

(i) When x=2x=2, y=3y = -3.
(ii) Graph: (Cannot draw the graph here)
(iii) Turning point: (1,4)(1, -4)
(iv) Roots: x=1x = -1 and x=3x = 3
(v) When 1x1-1 \le x \le 1, yy is decreasing.