Definition:Direction Ratios

Definition

Let $\LL$ be a line embedded in a Cartesian $3$-space.

Let $l$, $m$ and $n$ be the direction cosines of $\LL$ with respect to the $x$-axis, $y$-axis and $z$-axis respectively.

Direction ratios of $\LL$ are the three numbers in the ratio $l : m : n$.

Also known as

Direction ratios are also known as direction numbers.

Also see

• Results about direction ratios can be found here.

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): direction angles
• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): direction ratios
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): direction angles
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): direction ratios