AP_TECS: correct comment explaining roll-induced-drag scaling

Co-authored-by: George Zogopoulos <[email protected]>

libraries/AP_TECS/AP_TECS.cpp

@@ -751,7 +751,7 @@ void AP_TECS::_update_throttle_with_airspeed(void)
         const float nomThr = aparm.throttle_cruise * 0.01f;
         const Matrix3f &rotMat = _ahrs.get_rotation_body_to_ned();
         // Use the demanded rate of change of total energy as the feed-forward demand, but add
-        // additional component which scales with (1/cos(bank angle) - 1) to compensate for induced
+        // additional component which scales with (1/(cos(bank angle)**2) - 1) to compensate for induced
         // drag increase during turns.
         const float cosPhi_squared = (rotMat.a.y*rotMat.a.y) + (rotMat.b.y*rotMat.b.y);
         STEdot_dem = STEdot_dem + _rollComp * (1.0f/constrain_float(cosPhi_squared, 0.1f, 1.0f) - 1.0f);
@@ -905,7 +905,7 @@ void AP_TECS::_update_throttle_without_airspeed(int16_t throttle_nudge, float pi
     // Calculate additional throttle for turn drag compensation including throttle nudging
     const Matrix3f &rotMat = _ahrs.get_rotation_body_to_ned();
     // Use the demanded rate of change of total energy as the feed-forward demand, but add
-    // additional component which scales with (1/cos(bank angle) - 1) to compensate for induced
+    // additional component which scales with (1/(cos(bank angle)**2) - 1) to compensate for induced
     // drag increase during turns.
     const float cosPhi_squared = (rotMat.a.y*rotMat.a.y) + (rotMat.b.y*rotMat.b.y);
     float STEdot_dem = _rollComp * (1.0f/constrain_float(cosPhi_squared, 0.1f, 1.0f) - 1.0f);