diff --git a/KMA M1/4. Derivace funkce.md b/KMA M1/4. Derivace funkce.md
index a7ce374..0404b52 100644
--- a/KMA M1/4. Derivace funkce.md	
+++ b/KMA M1/4. Derivace funkce.md	
@@ -13,16 +13,16 @@
 | $\log_{a} x$        | $\frac{1}{x \ln a}$         |
 | $\sin x$            | $\cos x$                    |
 | $\cos x$            | $-\sin x$                   |
-| $\mbox{tg } x$      | $\frac{1}{\cos^2 x}$        |
-| $\mbox{cotg } x$    | $-\frac{1}{\sin^2 x}$       |
+| $\text{tg } x$      | $\frac{1}{\cos^2 x}$        |
+| $\text{cotg } x$    | $-\frac{1}{\sin^2 x}$       |
 | $\arcsin x$         | $\frac{1}{\sqrt{ 1-x^2 }}$  |
 | $\arccos x$         | $-\frac{1}{\sqrt{ 1-x^2 }}$ |
-| $\mbox{arctg } x$   | $\frac{1}{1+x^2}$           |
-| $\mbox{arccotg } x$ | $-\frac{1}{1+x^2}$          |
+| $\text{arctg } x$   | $\frac{1}{1+x^2}$           |
+| $\text{arccotg } x$ | $-\frac{1}{1+x^2}$          |
 | $\sinh x$           | $\cosh x$                   |
 | $\cosh x$           | $\sinh x$                   |
-| $\mbox{tgh } x$     | $\frac{1}{\cosh^2 x}$       |
-| $\mbox{cotgh } x$   | $\frac{1}{\sinh^2 x}$       |
+| $\text{tgh } x$     | $\frac{1}{\cosh^2 x}$       |
+| $\text{cotgh } x$   | $\frac{1}{\sinh^2 x}$       |
 
 ### Tečna a normála