Difference between revisions of "1993 AHSME Problems/Problem 12"

(Solution)
(Solution)
Line 10: Line 10:
  
 
== Solution ==
 
== Solution ==
As <math>f(2x)=\frac{2}{2+x}</math>, we have that <math>f(x)=\frac{2}{2+\frac{x}{2}}</math>. This also means that <math>2f(x)=\frac{4}{2+\frac{x}{2}}</math> which implies that the answer is <math>\fbox{E}</math>. ~ samrocksnature
+
As <math>f(2x)=\frac{2}{2+x}</math>, we have that <math>f(x)=\frac{2}{2+\frac{x}{2}}</math>. This also means that <math>2f(x)=\frac{4}{2+\frac{x}{2}}</math> which simplifies to <math>\fbox{E}</math>.  
  
 +
~ samrocksnature
 +
~ clarification my Leon
 
Note: Wait what
 
Note: Wait what
  

Revision as of 11:46, 3 June 2024

Problem

If $f(2x)=\frac{2}{2+x}$ for all $x>0$, then $2f(x)=$

$\text{(A) } \frac{2}{1+x}\quad \text{(B) } \frac{2}{2+x}\quad \text{(C) } \frac{4}{1+x}\quad \text{(D) } \frac{4}{2+x}\quad \text{(E) } \frac{8}{4+x}$

Solution

As $f(2x)=\frac{2}{2+x}$, we have that $f(x)=\frac{2}{2+\frac{x}{2}}$. This also means that $2f(x)=\frac{4}{2+\frac{x}{2}}$ which simplifies to $\fbox{E}$.

~ samrocksnature ~ clarification my Leon Note: Wait what

See also

1993 AHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 11
Followed by
Problem 13
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

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png