diff --git a/src/13_semiconductors_solutions.md b/src/13_semiconductors_solutions.md
index cf13b5ccaf202cb0bb3bfbfe99b42ebcd8ade367..3f56ac04ccc895949503170edff9ceb1331a2191 100644
--- a/src/13_semiconductors_solutions.md
+++ b/src/13_semiconductors_solutions.md
@@ -120,7 +120,7 @@ $$ E_{vb} \approx -t_{vb}(ka)^2 $$
 3.
 For the density of states for both the electrons and holes we find
 $$
-g_e(E) = \frac{1}{\pi a \sqrt{t_{cb}(E-E_G}}, \:\: \text{if} \:\: E > E_G,
+g_e(E) = \frac{1}{\pi a \sqrt{t_{cb}(E-E_G)}}, \:\: \text{if} \:\: E > E_G,
 $$
 and 
 $$