How to prove (a^c)^d = a^(cd) without knowing the values of c and d?

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SUMMARY

The discussion centers on proving the mathematical identity \((a^c)^d = a^{cd}\) without specific values for \(c\) and \(d\). Participants clarify that \(c\) and \(d\) are natural numbers, which simplifies the proof process. The key steps involve applying the laws of exponents, specifically \((ab)^n = (a^n)(b^n)\) and \(a^{p+n} = (a^p)(a^n)\). The user successfully completes the proof after receiving guidance on manipulating the expression using these exponent rules.

PREREQUISITES
  • Understanding of exponentiation rules, specifically \((ab)^n = (a^n)(b^n)\)
  • Familiarity with natural numbers and their properties
  • Basic algebraic manipulation skills
  • Knowledge of mathematical proofs and logical reasoning
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  • Study the properties of exponents in depth, focusing on proofs involving exponent rules
  • Explore mathematical induction as a technique for proving identities
  • Learn about the implications of natural numbers in algebraic expressions
  • Practice additional proof problems involving exponentiation and algebraic manipulation
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Students studying algebra, particularly those tackling proofs involving exponents, as well as educators looking for examples of teaching exponent rules effectively.

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Homework Statement



The problem is in the title: Prove (a^c)^d) = a^(cd)



Homework Equations



N is the set of natural numbers.

(ab)^n = (a^n)(b^n)
a^(p+n) = (a^p)*(a^n)
((a^p)(a^n)) * a = (a^p)(a^(n+1))

The Attempt at a Solution



c = p-q; d = j-k; p,q,j,kεN (by definition of integers)

(a^(p-q))^(j-k)

((a^(p-q))^j)/((a^(p-q))^k)

((a^(p+(-q)))^j)/((a^(p+ (-q)))^k)

((a^p)(a^(-q)))^j/((a^p)(a^(-q)))^k or (((a^p)/(a^q))^j)/(((a^p)/(a^q))^k)

I have no idea where to go from here. I've spent two hours on this and I've finished nearly all my other proofs on this assignment...This one is killing me though, and I have other work I need to get to at some point. Could anyone please give me a tip in the right direction? I feel like I have it all wrong.
 
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Welcome to PF!

Hi Llamas! Welcome to PF! :smile:

What are c and d, are they all natural (whole) numbers?

if so, just write ac = a times ac-1 :wink:
 


tiny-tim said:
Hi Llamas! Welcome to PF! :smile:

What are c and d, are they all natural (whole) numbers?

if so, just write ac = a times ac-1 :wink:

Thank you tiny-tim, the advice helped me finish the proof. Sorry I didn't respond until now, had other work as well.
 

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