equation test

docs/system/motor_thrust_model.md

@@ -8,8 +8,7 @@ nav_order: 1
 # Motor thrust model
 
 The MRS UAV System requires a model which can estimate the relation between a throttle input and thrust force produced by the rotors.
-e.g. the model tells us that when we use 0.6 throttle, we will get 30N of thrust.
-The throttle input is a value between 0 and 1, where 0 represents zero throttle, and 1 represents maximum throttle.
+e.g. the model tells us that when we use 0.6 (60%) throttle, we will get 30N of thrust.
 
 ## The model
 
@@ -18,3 +17,7 @@ The thrust is modelled as:
 When $a \ne 0$, there are two solutions to $(ax^2 + bx + c = 0)$ and they are 
 $$ x = {-b \pm \sqrt{b^2-4ac} \over 2a} $$
 
+% \f is defined as #1f(#2) using the macro
+\f\relax{x} = \int_{-\infty}^\infty
+    \f\hat\xi\,e^{2 \pi i \xi x}
+    \,d\xi