If →a,→b,→c are three unit vectors such that |→a+→b+→c|=1 and →a is perpendicular to →b. If →c makes angles α,β with →a,→b respectively, then (cosα+cosβ) is equal to

If →a,→b,→c are three unit vectors such that |→a+→b+→c|=1

1.	If →a,→b,→c are three unit vectors such that \|→a+→b+→c\|=1 and →a is perpendicular to →b. If →c makes angles α,β with →a,→b respectively, then (cosα+cosβ) is equal to
Answer» If $\to a, \to b, \to c$ are three unit vectors such that $\| \to a + \to b + \to c \| = 1$ and $\to a$ is perpendicular to $\to b .$ If $\to c$ makes angles $α, β$ with $\to a, \to b$ respectively, then $(cos α + cos β)$ is equal to