diff --git a/Analysis/Section_10_4.lean b/Analysis/Section_10_4.lean
index fd31378c..a3ff59e0 100644
--- a/Analysis/Section_10_4.lean
+++ b/Analysis/Section_10_4.lean
@@ -93,7 +93,7 @@ example (q:ℚ) : (nhdsWithin 1 (.Ici 0 \ {1})).Tendsto (fun x:ℝ ↦ (x^(q:ℝ
 example (α:ℝ) : (nhdsWithin 1 (.Ici 0 \ {1})).Tendsto (fun x:ℝ ↦ (x^α-1^α)/(x-1)) (nhds α) := by
   sorry
 
-/-- Exercise 10.4.2(b) -/
+/-- Exercise 10.4.3(b) -/
 example (α:ℝ) {x:ℝ} (hx: x ∈ Set.Ici 0) : HasDerivWithinAt (fun x:ℝ ↦ x^α) (α * x^(α-1)) (.Ici 0) x := by
   sorry