If Pand Q are complementary angles and P,Q,R are angles made by a straight line with X-,Y-and Z-axes respectively, then R=

If α,β,γ are the angles made by a line ‘L’ with the coordinate axes in the positive direction then Given α=P,β=π2−P,γ=RHence, cos2P+cos2π2−P+cos2R=1cos2P+sin2P+cos2R=1cos2R=0Therefore,R=π2