The direction cosines of the projections of the line x/(-2) = (y-1)/1 = (z+1)/(-1) on the plane 2x +y -3z =5 are
a. 2,-1,1
b. 2/(6)1/2,-1/(6)1/2,1/(6)1/2
c. -2/7,1/7,-1/7
d. 2/(6)1/2,-1/(6)1/2,1/(6)1/2
The direction ratios are (-2,1,-1)
So the corresponding directions cosines are,
So (d) is the answer.