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Ch. 7 - Transcendental Functions
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077Not the one you use?Change textbook
Chapter 7, Problem 7.8.1.c

1. Which of the following functions grow faster than e^x as x→∞? Which grow at the same rate as e^x? Which grow slower?
c. √x

Verified step by step guidance
1
Recall the growth rates of common functions as \(x \to \infty\). The exponential function \(e^x\) grows faster than any polynomial or root function.
Identify the function given: \(\sqrt{x}\), which is equivalent to \(x^{1/2}\), a root function and a type of power function.
Compare the growth of \(\sqrt{x}\) to \(e^x\). Since \(e^x\) grows exponentially and \(\sqrt{x}\) grows polynomially, \(e^x\) grows faster than \(\sqrt{x}\) as \(x \to \infty\).
Conclude that \(\sqrt{x}\) grows slower than \(e^x\) as \(x \to \infty\).
Summarize: \(\sqrt{x}\) does not grow faster than or at the same rate as \(e^x\); it grows slower.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Growth Rates of Functions

Growth rates describe how functions behave as the input approaches infinity. Comparing growth rates helps determine which functions increase faster, slower, or at the same pace. For example, exponential functions like e^x grow faster than polynomial or root functions as x→∞.
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Exponential Functions

Exponential functions have the form a^x, where the variable is in the exponent. The function e^x is a fundamental exponential function that grows rapidly as x increases. Its growth rate surpasses that of any polynomial or root function for large x.
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Polynomial and Root Functions

Polynomial functions involve variables raised to constant powers, while root functions are fractional powers (e.g., √x = x^(1/2)). These functions grow slower than exponential functions like e^x as x→∞, meaning their values increase but at a much slower rate.
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