diff --git a/Grade 10/Math/MPM2DZ/Trig Quiz 1.md b/Grade 10/Math/MPM2DZ/Trig Quiz 1.md
index e44a286..8ca4dc9 100644
--- a/Grade 10/Math/MPM2DZ/Trig Quiz 1.md	
+++ b/Grade 10/Math/MPM2DZ/Trig Quiz 1.md	
@@ -102,7 +102,7 @@ $`\cos(\beta) = \dfrac{AF}{AE} = \dfrac{AF}{1} = AF`$
 
 $`\text{Draw a parallel line to } CD \text{ that connects point } E \text{ to } AD. \quad \cos(\alpha + \beta) = \dfrac{BE}{AE} = \dfrac{BE}{1} = BE`$
 
-$`\therefore \sin(\alpha + \beta) = CD = CF + FD = \cos(\alpha) \sin(\beta) + \sin(\alpha) + \cos(\beta)`$
+$`\therefore \sin(\alpha + \beta) = CD = CF + FD = \cos(\alpha) \sin(\beta) + \sin(\alpha) \cos(\beta)`$
 
 $`\therefore \cos(\alpha + \beta) = BE = \cos(\alpha - \beta)`$
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