Find f such that f'(x) = f(x) = 7 √x f(16) = 70.

Calculus: Early Transcendentals
8th Edition
ISBN:9781285741550
Author:James Stewart
Publisher:James Stewart
Chapter1: Functions And Models
Section: Chapter Questions
Problem 1RCC: (a) What is a function? What are its domain and range? (b) What is the graph of a function? (c) How...
icon
Related questions
Question
### Problem Statement

Find the function \( f \) such that:

\[ f'(x) = \frac{7}{\sqrt{x}} \]

with the initial condition:

\[ f(16) = 70 \]

### Solution

Integrate \( f'(x) \) to find \( f(x) \):

Given:

\[ f'(x) = \frac{7}{\sqrt{x}} \]

First, rewrite the expression in a more familiar form for integration:

\[ f'(x) = 7x^{-\frac{1}{2}} \]

Integrate with respect to \( x \):

\[ f(x) = \int 7x^{-\frac{1}{2}} \, dx \]

Using the power rule for integration (\( \int x^n \, dx = \frac{x^{n+1}}{n+1} + C \)), we get:

\[ f(x) = 7 \cdot \int x^{-\frac{1}{2}} \, dx \]
\[ f(x) = 7 \cdot \left( \frac{x^{\frac{1}{2}}}{\frac{1}{2}} \right) + C \]
\[ f(x) = 7 \cdot 2x^{\frac{1}{2}} + C \]
\[ f(x) = 14\sqrt{x} + C \]

Next, utilize the initial condition to solve for \( C \):

Given:

\[ f(16) = 70 \]

Substitute \( x = 16 \) and \( f(16) = 70 \):

\[ 70 = 14\sqrt{16} + C \]
\[ 70 = 14 \cdot 4 + C \]
\[ 70 = 56 + C \]
\[ C = 14 \]

Thus, the function \( f(x) \) is:

\[ f(x) = 14\sqrt{x} + 14 \]


### Final Answer

\[ f(x) = 14\sqrt{x} + 14 \]
Transcribed Image Text:### Problem Statement Find the function \( f \) such that: \[ f'(x) = \frac{7}{\sqrt{x}} \] with the initial condition: \[ f(16) = 70 \] ### Solution Integrate \( f'(x) \) to find \( f(x) \): Given: \[ f'(x) = \frac{7}{\sqrt{x}} \] First, rewrite the expression in a more familiar form for integration: \[ f'(x) = 7x^{-\frac{1}{2}} \] Integrate with respect to \( x \): \[ f(x) = \int 7x^{-\frac{1}{2}} \, dx \] Using the power rule for integration (\( \int x^n \, dx = \frac{x^{n+1}}{n+1} + C \)), we get: \[ f(x) = 7 \cdot \int x^{-\frac{1}{2}} \, dx \] \[ f(x) = 7 \cdot \left( \frac{x^{\frac{1}{2}}}{\frac{1}{2}} \right) + C \] \[ f(x) = 7 \cdot 2x^{\frac{1}{2}} + C \] \[ f(x) = 14\sqrt{x} + C \] Next, utilize the initial condition to solve for \( C \): Given: \[ f(16) = 70 \] Substitute \( x = 16 \) and \( f(16) = 70 \): \[ 70 = 14\sqrt{16} + C \] \[ 70 = 14 \cdot 4 + C \] \[ 70 = 56 + C \] \[ C = 14 \] Thus, the function \( f(x) \) is: \[ f(x) = 14\sqrt{x} + 14 \] ### Final Answer \[ f(x) = 14\sqrt{x} + 14 \]
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps with 4 images

Blurred answer
Recommended textbooks for you
Calculus: Early Transcendentals
Calculus: Early Transcendentals
Calculus
ISBN:
9781285741550
Author:
James Stewart
Publisher:
Cengage Learning
Thomas' Calculus (14th Edition)
Thomas' Calculus (14th Edition)
Calculus
ISBN:
9780134438986
Author:
Joel R. Hass, Christopher E. Heil, Maurice D. Weir
Publisher:
PEARSON
Calculus: Early Transcendentals (3rd Edition)
Calculus: Early Transcendentals (3rd Edition)
Calculus
ISBN:
9780134763644
Author:
William L. Briggs, Lyle Cochran, Bernard Gillett, Eric Schulz
Publisher:
PEARSON
Calculus: Early Transcendentals
Calculus: Early Transcendentals
Calculus
ISBN:
9781319050740
Author:
Jon Rogawski, Colin Adams, Robert Franzosa
Publisher:
W. H. Freeman
Precalculus
Precalculus
Calculus
ISBN:
9780135189405
Author:
Michael Sullivan
Publisher:
PEARSON
Calculus: Early Transcendental Functions
Calculus: Early Transcendental Functions
Calculus
ISBN:
9781337552516
Author:
Ron Larson, Bruce H. Edwards
Publisher:
Cengage Learning