Thursday, February 21, 2019

algebra precalculus - Why does $ frac{1}{xsqrt{x}}= frac {sqrt{x}}{x^2} $?



A homework question recently asked for me to simplify:



$\frac{1}{\sqrt{7}} \div {7}$



It's easy to see that this becomes




$\frac{1}{7\sqrt{7}}$



But according to wolfram alpha this is also equal to $\frac{\sqrt{7}}{49}$.



What sequence of steps can I use to get the second representation of this quantity from the first?


Answer



$\dfrac{1}{\sqrt{7}}\div7=\dfrac{1}{7\sqrt{7}}=\dfrac{1}{7\sqrt{7}}\cdot\dfrac{\sqrt{7}}{\sqrt{7}}=\dots$


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