MathDB
Logarithm

Source: 1999 National High School Mathematics League, Exam One, Problem 3

March 9, 2020
logarithms

Problem Statement

If (log23)x(log53)x(log23)y(log53)y(\log_2 3)^x-(\log_5 3)^x\geq (\log_2 3)^{-y}-(\log_5 3)^{-y}, then (A)xy0(B)x+y0(C)xy0(D)x+y0\text{(A)}x-y\geq0\qquad\text{(B)}x+y\geq0\qquad\text{(C)}x-y\leq0\qquad\text{(D)}x+y\leq0