- PROVE THAT : 2 cos π/13 cos 9π/13 cos 3π/13 cos 5π/13 =0
- A beam is supported at its end by supports which are 12 meters apart.Scince the load is concentrated at its centre,there is a deflection of 3 cm at the centre and the deflected beam is in the shape of a parabola.How far from the centre is the deflection 1 cm.
