A triangle-factor reciprocal bound at fixed sum six
ProvedWorkbookSource.base_8188lean-workbooksource-checked
If a,b,c positive numbers and a+b+c=6 proove that
Source: InternLM Lean-Workbook, record lean_workbook_8188 (Apache-2.0). Complete source proposition preserved; proof developed independently.
Preamble
import Mathlib open Real Nat
Formal statement
theorem WorkbookSource.base_8188 (a b c : ℝ) (ha : 0 < a) (hb : 0 < b) (hc : 0 < c) (habc : a + b + c = 6) : 4 * (3 * (3 - a) * (3 - b) * (3 - c)) / a ^ 2 + 4 * (3 * (3 - b) * (3 - c) * (3 - a)) / b ^ 2 + 4 * (3 * (3 - c) * (3 - a) * (3 - b)) / c ^ 2 ≤ 7 / 2 * (a ^ 2 + b ^ 2 + c ^ 2) := by sorry
Source