In a quadrilateral PQRS, →PQ=→a,→QR=→b,→SP=→a−→b. M is the mid-point of QR and X is a point on SM such that →SX=45→SM, then →PX is
If the vectors →a and →b are perpendicular to each other, then a vector →v in terms of →a and →b satisfying the equations →v.→a=0,→v.→b=1 and [→v →a →b]=1 is