SOLUTION: if f(x) = 8^-x , what is the value of f(1/3)

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Question 935645: if f(x) = 8^-x , what is the value of f(1/3)
Found 2 solutions by Fombitz, josmiceli:
Answer by Fombitz(32388) About Me  (Show Source):
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+f%28x%29+=+8%5E%28-x%29+
+f%281%2F3%29+=+8%5E%28-1%2F3%29+
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The general rule for negative
exponents is:
+a%5E%28-b%29+=+1%2Fa%5Eb+ so,
+8%5E%28-1%2F3%29+=+1%2F%28+8%5E%281%2F3%29%29+
+1%2Froot%28+3%2C8+%29+=+1%2F2+ answer
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If I didn't know this, I would have
to use a calculator, for example:
+root%28+4%2C8+%29+ = ???