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Ch. 3 - Derivatives
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077Not the one you use?Change textbook
Chapter 3, Problem 3.9

Find the derivatives of the functions in Exercises 1–42.
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s = √ t .
1 + √ t

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1
Identify the function for which you need to find the derivative. In this case, the function is \( s = \sqrt{t} (1 + \sqrt{t}) \).
Rewrite the function in a more convenient form for differentiation. Express \( \sqrt{t} \) as \( t^{1/2} \), so the function becomes \( s = t^{1/2} (1 + t^{1/2}) \).
Apply the distributive property to expand the function: \( s = t^{1/2} + t^{1/2} \cdot t^{1/2} = t^{1/2} + t^{1} \).
Differentiate each term separately using the power rule. The power rule states that the derivative of \( t^n \) is \( n \cdot t^{n-1} \).
For the first term \( t^{1/2} \), the derivative is \( \frac{1}{2} t^{-1/2} \). For the second term \( t^1 \), the derivative is \( 1 \cdot t^{0} = 1 \). Combine these results to find the derivative of the function.

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Key Concepts

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

Derivative

The derivative of a function measures how the function's output value changes as its input value changes. It is defined as the limit of the average rate of change of the function over an interval as the interval approaches zero. Derivatives are fundamental in calculus for understanding rates of change and are denoted as f'(x) or dy/dx.
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Derivatives

Chain Rule

The chain rule is a formula for computing the derivative of the composition of two or more functions. It states that if you have a function g(x) that is composed with another function f(u), the derivative is found by multiplying the derivative of the outer function by the derivative of the inner function. This is essential when differentiating functions that involve square roots or other composite forms.
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Intro to the Chain Rule

Power Rule

The power rule is a basic rule for finding the derivative of a function in the form of f(x) = x^n, where n is any real number. According to this rule, the derivative is f'(x) = n*x^(n-1). This rule simplifies the process of differentiation, especially for polynomial functions and functions involving roots, making it easier to find derivatives quickly.
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