Explanation of a simple exponent rule in a derivative problem needed

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Homework Help Overview

The discussion revolves around the application of exponent rules in the context of derivatives, specifically focusing on simplifying expressions that involve powers in both the numerator and denominator.

Discussion Character

  • Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to understand the property that allows for the combination of exponents from the numerator and denominator in their derivative simplification. Some participants reference the rules of exponents and provide examples of how to apply these rules to the given expression.

Discussion Status

Participants have engaged in clarifying the exponent rules and how they apply to the problem at hand. The original poster expresses a newfound understanding after the discussion, indicating that helpful guidance has been provided regarding the application of exponent rules.

Contextual Notes

The original poster notes specific formatting of the expressions involved, which may have contributed to their confusion regarding the application of the exponent rules.

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Explanation of a "simple" exponent rule in a derivative problem needed

After differentiation, I get this : 9(t-2/2t+1)8 * 5/(2t+1)2

Now this simplifies into 45(t-2)/(2t+1)10

Now, I am wondering what the property is that combines the exponent from the top with the bottom to get an power of 10 in the simplified form.

*Note. the t-2/2t+1 is t-2 over 2t+1, the 5/(2t+1)2 is 5 over (2t+1)2, and the 45(t-2)/(2t+1)10 is 45(t-2) over (2t+1)10.
 
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From the rules of exponents:

[itex]a^n a^m = a^{n+m}[/itex]
 


if you start with [tex]9 (\frac{t-2}{2t+1})^8 * \frac{5}{(2t+1)^2}[/tex]
then you can write [tex]9 \frac{(t-2)^8}{(2t+1)^8}* \frac{5}{(2t+1)^2}[/tex]
and then you add the exponents when multiplying like bases, thus getting [tex]45 \frac{(t-2)^8}{(2t+1)^{10}}[/tex]

Note that [tex](2t+1)^8(2t+1)^2=(2t+1)^{10}[/tex]

edit:
boo, pibond beat me cause I'm slow at latex! :P
 
Last edited:


Thank you. I was aware of the rule for exponents, but applying the power of 8 to both the numerator and denominator escaped me, now it all makes sense!
 

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