/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 104 The growth of a red oak tree is ... [FREE SOLUTION] | 91Ó°ÊÓ

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The growth of a red oak tree is approximated by the function $$ \begin{array}{l}{G=-0.003 t^{3}+0.137 t^{2}+0.458 t-0.839} \\ {2 \leq t \leq 34}\end{array} $$ where \(G\) is the height of the tree (in feet) and \(t\) is its age (in years). (a) Use a graphing utility to graph the function. (b) Estimate the age of the tree when it is growing most rapidly. This point is called the point of diminishing returns because the increase in size will be less with each additional year. (c) Using calculus, the point of diminishing returns can be found by finding the vertex of the parabola $$ y=-0.009 t^{2}+0.274 t+0.458 $$ Find the vertex of this parabola. (d) Compare your results from parts (b) and (c).

Short Answer

Expert verified
To find when the tree is growing most rapidly, first graph the function and visually estimate this point. Then, calculate it using calculus by finding the vertex of the given parabola. The point of maximum growth should coincide visually and analytically, if done correctly.

Step by step solution

01

Graph the Function

To graph the function \( G \), a graphing utility can be used. The function is \( G = -0.003t^{3} + 0.137t^{2} + 0.458t - 0.839 \), for \( 2 \leq t \leq 34 \).
02

Estimate the Point of Maximum Growth

By observing the graph obtained in step one, we can estimate the value of \( t \) at which the graph achieves its maximum value. This is the age of the tree at which it grows most rapidly.
03

Find the Vertex of the Parabola

The vertex of the parabola \( y = -0.009t^{2} + 0.274t + 0.458 \) can be found by using the formula for the x-coordinate of the vertex of a parabola, \( t = -b/(2a) \), where \( a \) and \( b \) are coefficients of the quadratic and linear terms respectively. Substituting the values gives \( t = -0.274 / (2*(-0.009)) \). Calculating this will give us the exact value of \( t \) when the tree is growing most rapidly.
04

Compare the Results

Compare the value of \( t \) obtained in step 2 and step 3 and they should be approximately equal if the graphical estimation was done correctly.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Point of Diminishing Returns
In the context of the growth of a red oak tree, the point of diminishing returns refers to the age at which the tree's growth is at its most rapid. After this point, although the tree will continue to grow, the rate of growth will begin to decrease year over year. This concept is crucial in understanding the natural constraints and limitations of growth processes.
The point of diminishing returns helps in identifying a change in trend where the effort or input no longer results in proportional increases. Specifically for this exercise, it provides insights into biological growth patterns and helps to forecast how the tree will develop in the subsequent years. It represents a transition point that has implications in a broad range of fields including economics and biology.
Vertex of a Parabola
The vertex of a parabola is a significant characteristic of quadratic functions. It can be found in the formula of a quadratic function, which is typically in the form:
\( y = ax^2 + bx + c \).
For this exercise, the parabola in question is described by the equation \( y = -0.009t^2 + 0.274t + 0.458 \). The vertex of this parabola gives the point at which the growth of the tree is most rapid. This can be calculated using the formula for the x-coordinate:
  • \( t = \frac{-b}{2a} \), where \( a \) and \( b \) are the coefficients of the quadratic term and the linear term respectively.
Plugging in the values \( -0.009 \) and \( 0.274 \), we find that \( t = \frac{-0.274}{2 * -0.009} \). This computation leads to the exact time when the tree's growth reaches its peak speed.
Graphing Utilities
Graphing utilities are powerful tools used in mathematics to help visualize functions and their behaviors. They are especially useful in analyzing complex equations like the cubic function given for the red oak tree growth. By inputting the equation into a graphing calculator or software, we can generate a visual representation of the tree's height as it changes over time.
For the exercise at hand, using a graphing utility allows us to observe where the slope of the graph is steepest, indicating the point of maximum growth. This visual assessment makes it easier to estimate critical points, such as the point of diminishing returns, even before using calculus for precise calculations. Thus, graphing utilities are invaluable for verifying solutions and providing a clearer understanding of functional behaviors.
Calculus Applications
Calculus provides a robust framework for analyzing changes and finding critical points in various scenarios, such as the growth of a tree. In this exercise, calculus techniques are employed to find the exact point of diminishing returns by determining the vertex of a parabola that models the growth function.
The derivative of a function gives us the rate of change, and its maximum or minimum points are where this rate changes direction. By calculating the vertex of the derived quadratic function \( y = -0.009t^2 + 0.274t + 0.458 \), calculus helps pinpoint the exact time when the change in growth rate is most significant.
In broader terms, calculus plays a critical role in fields such as physics, economics, and engineering by offering tools to predict and optimize outcomes in dynamic systems. Here, it provides detailed insights into the natural growth rate of the tree, showcasing its potential for application in real-world situations.

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