The magnitudes of two vectors and differ by 1. The magnitude of their resultant makes an angle of tan–1(3/4) with P. The angle between P and Q is

(i) P - Q =1(ii)Tan α = 3/4 = Qsinθ /P+Qcosθwhere θ is the angle between P and Q , α is the angle between P and R∴ When θ = 900 can only satisfy both the conditions (i) & (ii)