`ABC` is triangle, right angled at A. The resultant of the forces acting along `vec(AB). vec(AC)` with magnitudes `1/(AB)` and respectively is the force along `vec(AD),` where D is the foot of the perpendicular from A onto BC. The magnitude of the resultant is-

Options

A. `((AB)(AC))/(AB+BC)`
B. `1/(AB)+1/(AC)`
C. `1/(AD)`
D. `((AB)^(2)+(AC)^(2))/((AB)^(2).(AC)^(2))`

Answer

C