Expression 3: "F" left parenthesis, "x" , right parenthesis equals StartFraction, left parenthesis, phi Superscript, 1 , Baseline "x" undefined minus left parenthesis, negative phi Subscript, 0 , Baseline , right parenthesis Superscript, "x" , Baseline , right parenthesis Over StartRoot, 5 , EndRoot , EndFractionFx=ϕx1−−ϕ0x5
3
Expression 4: "f" left parenthesis, "x" , right parenthesis equals StartFraction, left parenthesis, phi Superscript, 1 , Baseline "x" undefined minus cos left parenthesis, pi "x" , right parenthesis phi Superscript, 0 , Baseline "x" undefined , right parenthesis Over StartRoot, 5 , EndRoot , EndFractionfx=ϕx1−cosπxϕx05
4
Expression 5: "l" left parenthesis, "x" , right parenthesis equals left parenthesis, phi Superscript, 1 , Baseline "x" undefined plus cos left parenthesis, pi "x" , right parenthesis phi Superscript, 0 , Baseline "x" undefined , right parenthesislx=ϕx1+cosπxϕx0