Here is the shortest method possible:
if (Math.abs(v-550)<50) console.log('short')
if ((v-500)*(v-600)<0) console.log('short')
Parametrized:
if (Math.abs(v-max+v-min)<max+min) console.log('short')
if ((v-min)*(v-max)<0) console.log('short')
You can divide both sides by 2 if you don't understand how the first one works;)