lean_workbook_plus_51902

Proved

by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

Verify that $f(-1) = 6$ for the function $f(x)=-\frac{4}{3}x^{2}-\frac{14}{3}x+\frac{8}{3}$ .

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_51902 (f : ℝ → ℝ) (f_def : f = fun x => -(4/3)*x^2 -(14/3)*x + (8/3)) : f (-1) = 6   :=  by sorry

Source