" If the angle between the lines whose direction ratios are "2,-1,2" and "a,3,5" be "45^(@)" ,then "a=

Find the angle between the lines whose direction ratios are: 2,-3,4 and 1,2,1 .

Find the angle between the lines, whose direction ratios are 2,3,6 and 1,2,2.

Find the angle between the lines whose direction ratios are 2, 1, -2 and 3, -4, 5.

Find the angles between the lines whose direction ratios are 3,2,-6 and 1,2,2.

Find the angle between the lines whose direction ratios are 2, 3, 6 and 1, 2, 2

Find the angle between the lines whose direction ratios are 5, -12, 13 and -3, 4, 5

Find the acute angle between two lines whose direction ratios are and

If the angle between the lines whose direction ratios are (2,-1,2) and (x,3,5) is pi/4 , then the smaller value of x is