Finding the derivative of g(x)

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Homework Help Overview

The problem involves finding the derivative of the function g(x) defined as g(x) = f(3x), where f(x) is a continuous and differentiable function. The original poster seeks to determine g'(0.1) using provided values of f'(x).

Discussion Character

  • Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to apply the derivative directly by substituting values, while others suggest using the chain rule to find g'(x). There is discussion about the correct application of differentiation rules in this context.

Discussion Status

Participants are exploring different interpretations of the derivative, with some confirming the original poster's approach while others provide alternative reasoning based on the chain rule. There is acknowledgment of the correct application of calculus principles, but no consensus has been reached on the final answer.

Contextual Notes

There is a reference to a table of values for f'(x) that is not included in the discussion, which may affect the completeness of the reasoning. Additionally, the original poster notes a lapse in recalling the chain rule, indicating a potential gap in understanding that is being addressed through the discussion.

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Homework Statement



Let f(x) be a continuous and differentiable function on the interval 0 ≤ x ≤ 1, and let g(x)=f(3x). The table below gives values of f'(x), the derivative of f(x). What is the value of g'(0.1)?

http://img845.imageshack.us/img845/442/33806538.jpg

Homework Equations


The Attempt at a Solution



g(0.1) = f(3(0.1))
g(0.1) = f(0.3)
g'(0.1) = f'(0.3)
g'(0.1) = 1.096

Did I do the problem correctly? Thanks!
 
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Look correct assuming the picture and problems statement are what you have shown.
 
I think the answer should be E. g'(x) = 3*f'(3x). So, g'(0.1)=3*f'(0.3)=3*1.096=3.288
 
^ Actually that's correct because of the chain rule (haven't taken calculus in 5 years lol)

g(x) = f(u), where u = 3x so
g'(x) = f'(u)du = f'(3x)*3
 
shuohg said:
I think the answer should be E. g'(x) = 3*f'(3x). So, g'(0.1)=3*f'(0.3)=3*1.096=3.288

tazzzdo said:
^ Actually that's correct because of the chain rule (haven't taken calculus in 5 years lol)

g(x) = f(u), where u = 3x so
g'(x) = f'(u)du = f'(3x)*3



Thank you guys!
Forgot to use chain rule, thought I could just multiply 3*(0.3)
 

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