MathDB
Finding Rational Numbers

Source:

June 13, 2009
geometry3D geometry

Problem Statement

Which of these four numbers \sqrt{\pi^2},\,\sqrt[3]{.8},\,\sqrt[4]{.00016},\,\sqrt[3]{\minus{}1}\cdot \sqrt{(.09)^{\minus{}1}}, is (are) rational: <spanclass=latexbold>(A)</span> none<spanclass=latexbold>(B)</span> all<spanclass=latexbold>(C)</span> the first and fourth<spanclass=latexbold>(D)</span> only the fourth<spanclass=latexbold>(E)</span> only the first <span class='latex-bold'>(A)</span>\ \text{none}\qquad <span class='latex-bold'>(B)</span>\ \text{all}\qquad <span class='latex-bold'>(C)</span>\ \text{the first and fourth}\qquad <span class='latex-bold'>(D)</span>\ \text{only the fourth}\qquad <span class='latex-bold'>(E)</span>\ \text{only the first}