Difference between revisions of "1958 AHSME Problems/Problem 5"

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==Solution==
 
==Solution==
 
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We have
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<cmath>\begin{align*}2+\sqrt{2}+\frac{2-\sqrt{2}}{4-2}+\frac{\sqrt{2}+2}{2-4}&=2+\sqrt{2}+\frac{1}{2}(2-\sqrt{2})-\frac{1}{2}(\sqrt{2}+2)\\&=\frac{1}{2}(2+\sqrt{2}+2-\sqrt{2})\\&= \boxed{\text{(A) }2}.</cmath>
  
 
==See also==
 
==See also==
  
 
{{AHSME box|year=1958|num-b=4|num-a=6}}
 
{{AHSME box|year=1958|num-b=4|num-a=6}}

Revision as of 13:19, 4 June 2011

Problem

The expression $2 + \sqrt{2} + \frac{1}{2 + \sqrt{2}} + \frac{1}{\sqrt{2} - 2}$ equals:

$\textbf{(A)}\ 2\qquad  \textbf{(B)}\ 2 - \sqrt{2}\qquad  \textbf{(C)}\ 2 + \sqrt{2}\qquad  \textbf{(D)}\ 2\sqrt{2}\qquad  \textbf{(E)}\ \frac{\sqrt{2}}{2}$

Solution

We have

\begin{align*}2+\sqrt{2}+\frac{2-\sqrt{2}}{4-2}+\frac{\sqrt{2}+2}{2-4}&=2+\sqrt{2}+\frac{1}{2}(2-\sqrt{2})-\frac{1}{2}(\sqrt{2}+2)\\&=\frac{1}{2}(2+\sqrt{2}+2-\sqrt{2})\\&= \boxed{\text{(A) }2}. (Error compiling LaTeX. Unknown error_msg)

See also

1958 AHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 4
Followed by
Problem 6
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
All AHSME Problems and Solutions