Difference between revisions of "2002 AMC 12P Problems/Problem 20"

(Problem)
(Problem)
Line 2: Line 2:
 
Let <math>f</math> be a real-valued function such that
 
Let <math>f</math> be a real-valued function such that
 
<cmath>f(x) + 2f(\frac{2002}{x}) =3x</cmath>
 
<cmath>f(x) + 2f(\frac{2002}{x}) =3x</cmath>
 +
for all <math>x>0.</math> Find <math>f(2).</math>
 +
 
<math>
 
<math>
 
\text{(A) }1000
 
\text{(A) }1000

Revision as of 00:01, 30 December 2023

Problem

Let $f$ be a real-valued function such that \[f(x) + 2f(\frac{2002}{x}) =3x\] for all $x>0.$ Find $f(2).$

$\text{(A) }1000 \qquad \text{(B) }2000 \qquad \text{(C) }3000 \qquad \text{(D) }4000 \qquad \text{(E) }6000$

Solution

If $\log_{b} 729 = n$, then $b^n = 729$. Since $729 = 3^6$, $b$ must be $3$ to some factor of 6. Thus, there are four (3, 9, 27, 729) possible values of $b \Longrightarrow \boxed{\mathrm{E}}$.

See also

2002 AMC 12P (ProblemsAnswer KeyResources)
Preceded by
Problem 19
Followed by
Problem 21
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
All AMC 12 Problems and Solutions

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