Friday, September 20, 2019

algebra precalculus - What is sqrt4sqrt9?




I assumed that since acbc=(ab)c, then something like 49 would be 49=36=±6 but according to Wolfram Alpha, it's 6?


Answer



The property acbc=(ab)c that you mention only holds for integer exponents and nonzero bases. Since 4=(4)1/2, you cannot use this property here.



Instead, use imaginary numbers to evaluate your expression:



49=(2i)(3i)=6i2=6


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