/*! 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 47 Biology Buntin and colleagues \(... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Biology Buntin and colleagues \(^{92}\) showed that the net photosynthetic rate \(y\) of tomato leaves was approximated by the equation \(y=f(x)=8.094(1.053)^{-x},\) where \(x\) is the number of immature sweet potato whiteflies per square centimeter on tomato leaflets. Find \(f^{\prime}(x),\) and explain the significance of the sign of the derivative.

Short Answer

Expert verified
The derivative \( f'(x) \) is negative, indicating photosynthesis decreases as whiteflies increase.

Step by step solution

01

Identify the Function

We start with the function given in the problem, which describes the net photosynthetic rate of tomato leaves. The function is \( y = f(x) = 8.094(1.053)^{-x} \), where \( x \) is the number of immature sweet potato whiteflies per square centimeter.
02

Understand the Goal

We need to find the derivative of the function, \( f'(x) \), and interpret the significance of the sign of the derivative.
03

Differentiate the Function

To find \( f'(x) \), apply the chain rule to differentiate the function. Let \( u(x) = -x \), then \( y = 8.094(1.053)^{u(x)} \). The derivative of the exponential function \((a^u)' = a^u \ln a \cdot u'(x)\).
04

Apply Chain Rule

Since \( u(x) = -x \), we have \( u'(x) = -1 \). Thus, the derivative of \( y \) becomes: \( f'(x) = 8.094 \, (1.053)^{-x} \, \ln(1.053) \, (-1) \).
05

Simplify the Derivative

Simplify the expression for the derivative: \[ f'(x) = -8.094 \, (1.053)^{-x} \, \ln(1.053) \]. This represents the rate of change of the photosynthetic rate with respect to the number of whiteflies.
06

Examine Significance of the Derivative's Sign

The sign of \( f'(x) \) is negative (as indicated by the negative sign in front of the whole expression). This means that as \( x \) increases, the net photosynthetic rate \( y \) decreases. Essentially, more whiteflies lead to less effective photosynthesis.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

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

Exponential Function
The exponential function is a type of mathematical expression where a constant base is raised to a variable exponent. In the context of this exercise, the function representing the net photosynthetic rate of tomato leaves is an exponential function. It's given by:
  • \( y = 8.094(1.053)^{-x} \)
Here, the base is 1.053, and the exponent is the negative of the variable \( x \). This means that the rate at which something is happening decreases with each additional unit of \( x \). In this instance, each additional immature sweet potato whitefly per square centimeter leads to a reduction in the photosynthetic rate of tomato leaves.
Understanding exponential functions involves recognizing how changes in the exponent affect the overall value. Often, these functions model situations where there's exponential growth or decay. In our case, the presence of more whiteflies leads to an exponential decay in the rate of photosynthesis.
Chain Rule
In calculus, the chain rule is a fundamental technique for differentiating composite functions. It's particularly useful when you're dealing with something complex, like our exponential function. To differentiate a function like \( y = 8.094(1.053)^{-x} \), the chain rule breaks it down.
  • First, identify \( u(x) = -x \).
  • Find the derivative of \( u(x) \), which is \( u'(x) = -1 \).
  • Apply the chain rule to find the derivative of \( y \), which means differentiating the outside function and multiplying it by the derivative of \( u(x) \).
This gives us the derivative:
  • \[ f'(x) = 8.094 \, (1.053)^{-x} \, \ln(1.053) \, (-1) \]
The chain rule allows one to handle the function's nested nature efficiently, aiding in calculating how fast the photosynthetic rate is changing.
Photosynthesis Rate
The rate of photosynthesis is a crucial metric in plant biology. It indicates how efficiently a plant converts light energy into chemical energy, essential for its growth and survival. In this problem, the function \( y = 8.094(1.053)^{-x} \) models this rate based on the number of whiteflies present.
The photosynthesis rate decreases as the density of immature sweet potato whiteflies increases due to their detrimental effects like shading and feeding on leaf sap. The decline follows an exponential decay, as indicated by the function's structure. The derivative \( f'(x) \) further illustrates this decrease, showing how sensitive photosynthesis is to environmental stressors like insect infestations.
Efficient photosynthesis is critical because it underpins plant health and productivity, impacting both the natural ecosystem and agricultural yields.
Biology Application
In biology, understanding how organisms interact with their environment is crucial. Applying calculus to biological problems offers insights into these interactions, such as how pest populations might affect crops. This mathematical approach can predict outcomes like those seen in photosynthesis rates.
  • Researchers use such models to predict how varying conditions impact plant behaviors.
  • By knowing the rate of change, scientists and farmers can devise strategies to mitigate adverse effects, such as managing whitefly populations to ensure optimal plant growth.
This exercise represents a biology application where calculus helps bridge math with real-world scenarios, emphasizing the interdisciplinary nature of modern scientific study. It underscores how mathematical tools can guide practical decisions, especially in agriculture and ecology.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

In this section we considered demand \(x\) as a function \(x=f(p)\) of price and then defined the elasticity as \(E=-\frac{p}{x} \frac{d x}{d p} .\) But demand is also a function of other variables. For example, Cotterill and Haller \({ }^{79}\) recently found that the demand \(x\) for the breakfast cereal Shredded Wheat was approximately related to the amount \(a\) of coupons issued by \(x=B a^{0.0229}\), where \(B\) is a constant. Define an elasticity with respect to coupons in a way analogous to what was done for demand with respect to price. Find the elasticity with respect to couponing in this case, and explain in words what it means.

Taplin \(^{95}\) showed that if \(Y\) is dollars spent overseas, then the equation \(Y=A X^{0.7407}\) approximately held, where \(X\) is household disposable income in dollars per week and \(A\) is a constant. Explain in words what the exponent 0.7407 means.

Economies of Scale In 1955 Surdis \(^{87}\) obtained records from a utility company regarding its trench digging operations. The records show that the unit cost \(C(n)\) per foot of earth removed by the mechanical trencher is given approximately by $$ C(n)=\frac{15.04+0.74 n}{25 n} $$ where \(n\) is the number of hours worked per day. a. Graph. Find values for \(C^{\prime}(n)\) at \(x=2,4,6,\) and \(8 .\) Interpret what these numbers mean. What is happening? Units costs for hand digging was found to be \(\$ 0.60 .\) b. Approximate the number of hours worked at which using the trench digging machinery is more cost effective than hand digging.

Biology Potter and colleagues \(^{23}\) showed that the percent mortality \(y\) of a New Zealand thrip was approximated by \(\quad y=f(T)=81.12+0.465 T-0.828 T^{2}+0.04 T^{3}\), where \(T\) is the temperature measured in degrees Celsius. Graph on your grapher using a window of dimensions [0,20] by [0,100] a. Estimate the value of the temperature where the tangent line to the curve \(y=f(T)\) is horizontal. b. Check your answer using calculus. (You will need to use the quadratic formula.) c. Did you miss any points in part (a)? d. Is this another example of how your computer or graphing calculator can mislead you? Explain.

Profits The daily profits in dollars of a firm are given by \(P=-10 x^{3}+800 x-10 e^{x},\) where \(x\) is the number of items sold. Find the instantaneous rate of change when \(x\) is (a) \(2,\) (b) \(3,\) (c) \(4,\) (d) 5 . Interpret your answers.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.