If a line has the direction ratios –18, 12, –4, then what are its direction cosines?

Question

Philoid · Accepted Answer

If the direction ratios of the line are a, b and c

Then the direction cosines are

Given direction ratios are – 18, 12 and – 4

⇒ a= -18, b = 12 and c= -4

=

Direction cosines are