The problem consists of four parts. Part 1: Given the function $y = (2+x)(x-4)$, we need to sketch the graph of the function and find the minimum value of $y$. Part 2: We need to factorize the equation $2x^2 + 5x - 3$ completely. Part 3: Given the graph of the function $y = 3 - 2x - x^2$, we need to find the coordinates of the points A and C.
2025/6/19
1. Problem Description
The problem consists of four parts.
Part 1: Given the function , we need to sketch the graph of the function and find the minimum value of .
Part 2: We need to factorize the equation completely.
Part 3: Given the graph of the function , we need to find the coordinates of the points A and C.
2. Solution Steps
Part 1:
i. Sketch the graph of
Expanding the equation, we have .
This is a parabola. The roots are and .
The x-coordinate of the vertex is the average of the roots: .
The y-coordinate of the vertex is found by substituting into the equation: .
The vertex is at .
The y-intercept is when , so .
Since the coefficient of is positive, the parabola opens upwards.
ii. Find the minimum value of .
The minimum value of occurs at the vertex of the parabola.
The y-coordinate of the vertex is . Therefore, the minimum value of is .
Part 2:
Factorize the equation .
We are looking for two numbers that multiply to and add up to . The numbers are and .
Rewrite the middle term: .
Factor by grouping: .
Factor out the common term : .
Part 3:
Find the coordinates of the points A and C.
The points A and C are the x-intercepts of the graph .
To find the x-intercepts, set : .
Multiply by : .
Factor the quadratic equation: .
The roots are and .
Since point A is to the left of the y-axis and C is to the right, and .
3. Final Answer
Part 1:
i. Sketch: A parabola with roots at and , vertex at and y-intercept at .
ii. Minimum value of
Part 2:
Part 3:
A = and C =