diff --git a/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/02.plane-refracting-surface-overview/cheatsheet.en.md b/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/02.plane-refracting-surface-overview/cheatsheet.en.md
index a52c22782..b0927a932 100644
--- a/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/02.plane-refracting-surface-overview/cheatsheet.en.md
+++ b/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/02.plane-refracting-surface-overview/cheatsheet.en.md
@@ -150,7 +150,9 @@ You know $`\overline{SA_{obj}}`$, $`n_{inc}`$ and $`n_{eme}`$, you have previous
 
 ! *USEFUL* : The conjuction equation and the transverse magnification equation for a plane refracting 
 !surface are obtained by rewriting these equations for a spherical refracting surface in the limit when
-! $`|\overline{SC}|\longrightarrow\infty`$.<br> Then we get *for a plane refracting surface :*
+!
+! $`|\overline{SC}|\longrightarrow\infty`$.<br> 
+! Then we get *for a plane refracting surface :*
 !
 ! * *conjuction equation :*&nbsp;&nbsp; $`\dfrac{n_{fin}}{\overline{SA_{ima}}}-\dfrac{n_{ini}}{\overline{SA_{obj}}}=0`$ &nbsp;&nbsp; (equ.3)
 !