Skip to main content
Ch. 3 - Derivatives
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Not the one you use?Change textbook
Chapter 3, Problem 3.4.99b

Product Rule for three functions Assume f, g, and h are differentiable at x.
b. Use the formula in (a) to find d/dx(e^x(x−1)(x+3))

Verified step by step guidance
1
Step 1: Identify the functions involved in the product. Here, we have three functions: \(f(x) = e^x\), \(g(x) = (x - 1)\), and \(h(x) = (x + 3)\). We need to differentiate the product \(f(x)g(x)h(x)\).
Step 2: Recall the product rule for three functions. If \(u(x)\), \(v(x)\), and \(w(x)\) are differentiable functions, then the derivative of their product is given by: \(\frac{d}{dx}[u(x)v(x)w(x)] = u'(x)v(x)w(x) + u(x)v'(x)w(x) + u(x)v(x)w'(x)\).
Step 3: Differentiate each function individually. Compute \(f'(x)\), \(g'(x)\), and \(h'(x)\). For \(f(x) = e^x\), \(f'(x) = e^x\). For \(g(x) = (x - 1)\), \(g'(x) = 1\). For \(h(x) = (x + 3)\), \(h'(x) = 1\).
Step 4: Apply the product rule for three functions. Substitute \(f(x)\), \(g(x)\), \(h(x)\), and their derivatives into the formula: \(\frac{d}{dx}[e^x(x-1)(x+3)] = e^x \cdot (x-1)(x+3) + e^x \cdot 1 \cdot (x+3) + e^x \cdot (x-1) \cdot 1\).
Step 5: Simplify the expression. Combine like terms and simplify the expression obtained in Step 4 to get the final derivative.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
5m
Was this helpful?

Key Concepts

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

Product Rule

The Product Rule is a fundamental differentiation rule used to find the derivative of the product of two or more functions. For two functions f(x) and g(x), the rule states that the derivative of their product is given by f'(x)g(x) + f(x)g'(x). This concept extends to three functions, where the derivative of f(x)g(x)h(x) is f'(x)g(x)h(x) + f(x)g'(x)h(x) + f(x)g(x)h'(x).
Recommended video:
05:18
The Product Rule

Chain Rule

The Chain Rule is another essential differentiation technique that allows us to differentiate composite functions. If a function y is defined as a composition of two functions, such as y = f(g(x)), the Chain Rule states that the derivative is dy/dx = f'(g(x)) * g'(x). While not directly applied in the product rule, understanding the Chain Rule is crucial when dealing with functions that involve exponentials or other nested functions.
Recommended video:
05:02
Intro to the Chain Rule

Exponential Functions

Exponential functions, such as e^x, are functions where the variable appears in the exponent. The derivative of e^x is unique because it is equal to e^x itself, making it particularly straightforward to differentiate. In the context of the given problem, recognizing that e^x is part of the product allows for easier application of the Product Rule, as its derivative does not change the form of the function.
Recommended video:
6:13
Exponential Functions
Related Practice
Textbook Question

Derivatives of inverse functions from a table Use the following tables to determine the indicated derivatives or state that the derivative cannot be determined. <IMAGE>

b. (f^-1)'(6)

200
views
Textbook Question

{Use of Tech} Bungee jumper A woman attached to a bungee cord jumps from a bridge that is 30 m above a river. Her height in meters above the river t seconds after the jump is y(t) = 15(1+e^−t cos t), for t ≥ 0.

b. Use a graphing utility to determine when she is moving downward and when she is moving upward during the first 10 s.  

256
views
Textbook Question

31–32. Velocity functions A projectile is fired vertically upward into the air, and its position (in feet) above the ground after t seconds is given by the function s(t).

b. Determine the instantaneous velocity of the projectile at t=1 and t = 2 seconds.

s(t)= −16t²+100t

196
views
Textbook Question

The Chain Rule for second derivatives

b. Use the formula in part (a) to calculate d2dx2(sin(3x4+5x2+2))\(\frac{d^2}{dx^2}\[\left\)(\(\sin\]\left\)(3x^4+5x^2+2\(\right\))\(\right\)).

408
views
Textbook Question

Throwing a stone Suppose a stone is thrown vertically upward from the edge of a cliff on Earth with an initial velocity of 32 ft/s from a height of 48 ft above the ground. The height (in feet) of the stone above the ground t seconds after it is thrown is s(t) = -16t²+32t+48.

b. When does the stone reach its highest point?

184
views
Textbook Question

Tracking a dive A biologist standing at the bottom of an 80-foot vertical cliff watches a peregrine falcon dive from the top of the cliff at a 45° angle from the horizontal (see figure). <IMAGE>


b. What is the rate of change of θ with respect to the bird’s height when it is 60 ft above the ground?

141
views