Ex 11.1, 1 - Chapter 11 Class 12 Three Dimensional Geometry

Transcript

Ex 11.1, 1 If a line makes angles 90 , 135 , 45 with the x, y and z axes respectively, find its direction cosines. Direction cosines of a line making angle with x axis, with y axis and with z axis are l , m , n l = cos , m = cos , n = cos Here, = 90 , = 135 , = 45 , So, direction cosines are l = cos 90 = 0 = cos 135 = cos(180 45 ) = cos 45 = 1 2 = cos 45 = 1 2 Therefore, required direction cosines are 0, , .