Confused - simple differentiation with simplification

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Homework Help Overview

The discussion revolves around differentiating the function y = x(x+2)(x+3), with participants expressing confusion regarding the correct derivative and the implications of the initial x in the expression.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants suggest multiplying the expression out before differentiating and question the validity of the provided answer. There is a focus on understanding how the initial x affects the differentiation process.

Discussion Status

Participants are actively engaging with the problem, with some expressing agreement on the need to reconsider the differentiation approach. There is acknowledgment that the derivative provided in the book may be incorrect, and alternative methods are being explored.

Contextual Notes

Some participants reference the use of online calculators for verification, indicating a potential lack of confidence in the textbook answer. The original problem's structure is being scrutinized for clarity.

chuffy
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Homework Statement


differentiate the following
y= x(x+2)(x+3)


Homework Equations


dy/dx


The Attempt at a Solution



The answer I'm given is dy/dx = 2x+5
Would this not be for (x+2)(x+3) = x2 +5x +6
dy/dx = 2x +5 +0

My problem is the x at the beginning of the brackets. Please help!
thanks
 
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Multiply the equation out and then differentiate, that answer given by the book doesn't seem right.
 
chuffy said:

Homework Statement


differentiate the following
y= x(x+2)(x+3)


Homework Equations


dy/dx


The Attempt at a Solution



The answer I'm given is dy/dx = 2x+5
Would this not be for (x+2)(x+3) = x2 +5x +6
dy/dx = 2x +5 +0

My problem is the x at the beginning of the brackets. Please help!
thanks


You're right. With the x at the beginning, the final answer is a quadratic expression.
 
Er...I think I agree actually. Once you multiply through by x, you get x^3 + 5x^2 + 6x.

The derivative of that is not what was given in the answer.
 
cheers guys I'm going nuts the question states x(x+2)(x+3)
with the answer of 2x+5
 
thanks for the above link
 

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