MathDB
Solving an Equation

Source:

February 7, 2009
trigonometry

Problem Statement

If \left (a\plus{}\frac{1}{a} \right )^2\equal{}3, then a^3\plus{}\frac{1}{a^3} equals: <spanclass=latexbold>(A)</span> 1033<spanclass=latexbold>(B)</span> 33<spanclass=latexbold>(C)</span> 0<spanclass=latexbold>(D)</span> 77<spanclass=latexbold>(E)</span> 63 <span class='latex-bold'>(A)</span>\ \frac{10\sqrt{3}}{3} \qquad <span class='latex-bold'>(B)</span>\ 3\sqrt{3} \qquad <span class='latex-bold'>(C)</span>\ 0 \qquad <span class='latex-bold'>(D)</span>\ 7\sqrt{7} \qquad <span class='latex-bold'>(E)</span>\ 6\sqrt{3}