Difference between revisions of "1983 AHSME Problems/Problem 8"

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== Solution ==
 
== Solution ==
<math>\frac{-x+1}{-x-1}\implies\frac{x-1}{x+1}=\frac{1}{f(x)}</math>, <math>\fbox{A}</math>
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We find <math>f(-x) = \frac{-x+1}{-x-1} = \frac{x-1}{x+1} = \frac{1}{f(x)}</math>, so the answer is <math>\boxed{\textbf{(A)}}</math>.
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==See Also==
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{{AHSME box|year=1983|num-b=7|num-a=9}}
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{{MAA Notice}}

Latest revision as of 23:45, 19 February 2019

Problem 8

Let $f(x) = \frac{x+1}{x-1}$. Then for $x^2 \neq 1, f(-x)$ is

$\textbf{(A)}\ \frac{1}{f(x)}\qquad \textbf{(B)}\ -f(x)\qquad \textbf{(C)}\ \frac{1}{f(-x)}\qquad \textbf{(D)}\ -f(-x)\qquad \textbf{(E)}\ f(x)$

Solution

We find $f(-x) = \frac{-x+1}{-x-1} = \frac{x-1}{x+1} = \frac{1}{f(x)}$, so the answer is $\boxed{\textbf{(A)}}$.

See Also

1983 AHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 7
Followed by
Problem 9
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


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