Let `A(-1, 2, 1) and B(4, 3, 5)` be two given points. Find the projection of AB on a line which makes angle `120^(@) and 135^(@)` with Yand Z-axes respectively, and an acute angle with X-axis.

P and Q are the points (-1,2,1) and (4,3,5) respectively.Find the projection of PQ on a line which makes angles of 120^(@) and 135^(@) with y and z -axes respectively and an acute angle with the x- axis.

If a line makes angles 90^(@),135^(@)and45^(@) with the X, Y and Z-axis respectively, find its direction cosines.

If a line makes angle (pi)/3 and (pi)/4 with x-axis and y-axis respectively then the angle made by the line with z-axis, is