Skip to main content

2003 AMC 10A Problem 9

Problem 9 of 25EasierAlgebra

Simplify xxxx333.\sqrt[3]{x\sqrt[3]{x\sqrt[3]{x\sqrt{x}}}}.

Answer choices

Show solution

Solution

Working outward, xx=x32,x\sqrt{x} = x^{\frac{3}{2}}, and its cube root is x12.x^{\frac{1}{2}}. Then xx12=x32,x \cdot x^{\frac{1}{2}} = x^{\frac{3}{2}}, whose cube root is again x12.x^{\frac{1}{2}}. Repeating once more, xx12=x32,x \cdot x^{\frac{1}{2}} = x^{\frac{3}{2}}, whose cube root is x12=x.x^{\frac{1}{2}} = \sqrt{x}. Thus, the correct answer is A.

More practice

Concepts: radical · exponent

Problem text and solution from the LIVE past-contest archive. See also the AoPS wiki page for community solutions.