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{
"index": "1998-B-1",
"question": "Find the minimum value of\n\\[\n\\frac{(x+1/x)^6-(x^6+1/x^6)-2}{(x+1/x)^3+(x^3+1/x^3)}\n\\]\nfor $x>0$.",
"solution": "Notice that\n\\[\n\\frac{(x+1/x)^6-(x^6+1/x^6)-2}{(x+1/x)^3+(x^3+1/x^3)}\n=(x+1/x)^3-(x^3+1/x^3)=3(x+1/x).\n\\]\nThe last expression has minimum value $6$ by AM-GM, achieved at $x=1$.",
"vars": [
"x"
],
"params": [],
"sci_consts": [],
"problem_type": "calculation",
"variants": {}
}
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