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1 vote
Find the indicated real n roots of a

N=4, a=81

User Jutky
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2 Answers

4 votes


81|3\\27|3\\.\ 9|3\\.\ 3|3\\.\ 1|\\\\81=\underbrace{3\cdot3\cdot3\cdot3}_(4)=3^4\\\\\sqrt[4]{81}=\sqrt[4]{3^4}=3\\\\Used:\\\sqrt[n]{a^n}=a

User Henny Lee
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4 votes

If I understood coorectly, you're looking for the fourth root of 81. This exercise can be solved by remembering that extracting the fourth root of a number is the same as raising that number to the power of 1/4.


We also need the prime factorization of 81, which is



81 = 9 * 9 = 3^2 * 3^2 = 3^4


So, the fourth root of 81 is 81 raised to the power of 1/4, which means



\sqrt[4]{81} = \sqrt[4]{3^4} = (3^4)^{(1)/(4)}


Now, use the property of exponents
(a^b)^c = a^(bc) to convert the expression into



(3^4)^{(1)/(4)} = 3^{4\cdot (1)/(4)} = 3^1 = 3

User Vadirn
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