Fix typo in spline documentation

src/Math/include/BipedalLocomotion/Math/CubicSpline.h

@@ -25,9 +25,9 @@ namespace Math
  * Cubic spline implements a 3-rd order polynomial spline in \$f\mathbb{R}^n\$f.
  * @note The spline is defined as a set of piecewise polynomial functions of degree 3 of the form
  * \f[
- * s(t) = a_0 + a_1 t + a_2 t^2 + a_3 t^3
+ * s_i(t) = a_i + b_i t + c_i t^2 + d_i t^3
  * \f]
- * where \$t \in [0, T_i]\$ and \$T_i\$ is the duration of the i-th polynomial.
+ * where \f$t \in [0, T_i]\f$ and \f$T_i\f$ is the duration of the i-th polynomial.
  */
 template <typename T> class CubicSpline : public Spline<T>
 {

src/Math/include/BipedalLocomotion/Math/LinearSpline.h

@@ -25,9 +25,9 @@ namespace Math
  * Linearspline implements a 1-st order polynomial spline in \$f\mathbb{R}^n\$f.
  * @note The spline is defined as a set of piecewise polynomial functions of degree 1 of the form
  * \f[
- * s(t) = a_0 + a_1 t
+ * s_i(t) = a_i + b_i t
  * \f]
- * where \$t \in [0, T_i]\$ and \$T_i\$ is the duration of the i-th polynomial.
+ * where \f$t \in [0, T_i]\f$ and \f$T_i\f$ is the duration of the i-th polynomial.
  */
 template <typename T> class LinearSpline : public Spline<T>
 {

src/Math/include/BipedalLocomotion/Math/QuinticSpline.h

@@ -27,7 +27,7 @@ namespace Math
  * \f[
  * s_i(t) = a_i + b_i t + c_i t^2 + d_i t^3 + e_i t^4 + f_i t^5
  * \f]
- * where \$t \in [0, T_i]\$ and \$T_i\$ is the duration of the i-th polynomial.
+ * where \f$t \in [0, T_i]\f$ and \f$T_i\f$ is the duration of the i-th polynomial.
  */
 template <typename T> class QuinticSpline : public Spline<T>
 {