Envelope Theorem · dV*/dθ = ∂V/∂θ at the Optimum
unseel.com · the choice-reaction term vanishes — first-order condition kills it
θ 1.00
V*(θ)
Beat
Family f(x, θ) — one curve per fixed x
Envelope V*(θ) = max_x f(x, θ)
Optimal choice x*(θ)
Tangent slope = ∂f/∂θ at x*
Unseel.com · Envelope Theorem