Chapter 3: Problem 35
ENVIRONMENTAL SCIENCE: Pollution Two chemical factories are discharging toxic waste into a large lake, and the pollution level at a point \(x\) miles from factory A toward factory B is \(P(x)=3 x^{2}-72 x+576\) parts per million (for \(0 \leq x \leq 50)\). Find where the pollution is the least.
Short Answer
Expert verified
The pollution is least at 12 miles from factory A with 72 ppm.
Step by step solution
01
Identify the problem
We are given a pollution level function \( P(x) = 3x^2 - 72x + 576 \) and need to find the point \( x \) where this function reaches its minimum value, which indicates the least pollution.
02
Recognize the function type
The function \( P(x) = 3x^2 - 72x + 576 \) is a quadratic function of the form \( ax^2 + bx + c \), where \( a = 3 \), \( b = -72 \), and \( c = 576 \). Quadratic functions are parabolas and since \( a > 0 \), this parabola opens upwards, meaning it has a minimum point.
03
Finding the vertex of the parabola
The vertex of a parabola given by \( ax^2 + bx + c \) is found at \( x = -\frac{b}{2a} \). Substitute \( b = -72 \) and \( a = 3 \) into the formula: \( x = \frac{72}{2 \times 3} = 12 \). Thus, the minimum pollution level occurs at \( x = 12 \) miles from factory A.
04
Verify the result
Ensure that the value \( x = 12 \) is within the given range \( 0 \leq x \leq 50 \). Since 12 is within this range, the solution is valid.
05
Calculate pollution level at minimum
Substitute \( x = 12 \) into the function to find the pollution level: \( P(12) = 3(12)^2 - 72(12) + 576 \). Simplifying, \( P(12) = 3(144) - 864 + 576 \), which equals \( 72 \) parts per million. This confirms that the pollution is least at \( x = 12 \) miles.
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Quadratic Functions
Quadratic functions are a special kind of polynomial that take the form of \( ax^2 + bx + c \). These functions create curves known as parabolas when graphed on a coordinate plane. Quadratic functions are widespread in various applications, including physics, engineering, and economics, because they can model relationships that involve squared terms.
- For a quadratic equation \( ax^2 + bx + c \), \( a \), \( b \), and \( c \) are constants, with \( a eq 0 \).
- If \( a > 0 \), the parabola opens upwards and has a minimum point, while if \( a < 0 \), it opens downwards and has a maximum point.
Vertex of Parabola
The vertex of a parabola plays a critical role in understanding the graph's behavior. Consider it the peak or the lowest point of the parabola, depending on whether it opens upwards or downwards.
- The vertex's x-coordinate can be calculated using the formula \( x = -\frac{b}{2a} \) for a quadratic function \( ax^2 + bx + c \).
- This point is vital for identifying the minimum or maximum value that the quadratic function attains.
Environmental Pollution
Environmental pollution is a pressing issue, often resulting from human activity and industrial processes. In many scenarios, mathematical models like quadratic functions help in assessing and optimizing the impact.
- Pollution levels in an ecosystem can be analyzed by mathematical expressions to determine areas of concern.
- Mathematics aids in strategizing efficient resource management and reducing pollution exposure.
Mathematical Modelling
Mathematical modeling transforms real-world problems into mathematical language, providing solutions through analysis and computation. This process is beneficial for predicting outcomes and making informed decisions.
- Models often employ equations like quadratic functions to portray physical, biological, or social systems.
- With mathematical models, we can simulate scenarios and examine the effects of different variables.