Write the direction cosines of the line joining the points (1,0,0) and (0,1,1).

The correct answer is $-\dfrac{1}{\sqrt{3}}$, $\dfrac{1}{\sqrt{3}}$, $\dfrac{1}{\sqrt{3}}$

Direction rations are (0-1), (1-0), (1-0) i.e. -1, 1, 1

∴ $\sqrt{(-1)^2 + 1^1 + 1^2}$ = $\sqrt{3}$

∴ Direction cosines are $-\dfrac{1}{\sqrt{3}}$, $\dfrac{1}{\sqrt{3}}$, $\dfrac{1}{\sqrt{3}}$