MathDB
Find the range of c satisfying an inequality.

Source: 2018 China Southeast MO Grade 10 P1

July 30, 2018
algebraInequalityinequalities

Problem Statement

Assume cc is a real number. If there exists x[1,2]x\in[1,2] such that max{x+cx,x+cx+2}5\max\left\{\left |x+\frac cx\right |, \left |x+\frac cx + 2\right |\right\}\geq 5, please find the value range of cc.