μ_k (x) =
left lbrace
matrix {
{(x-a_{k-1} )^4} over ( a_k – a_{k-1} )^4 , a_{k-1} ≤ -x ≤ a_k ##
{(x-a_{k+1} )^4} over ( a_{k+1} – a_k )^4 , a_k ≤ -x ≤ a{k+1}
}
latek
\(