Sub var1()
Dim fc, tc, pc, bc As Range
Set fc = Range("B1:B11")

Dim f, t, p, b As Double
Dim d, c, y As Double

Dim i As Integer
Dim x() As Variant

d = 1.89
c = 0.4
y = 1.6

x = Array(0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5)

For i = 0 To 9

    If x(i) > b Then
        t = (Cos(x(i)) ^ 2 + Sin(b))
    ElseIf x(i) <= b Then
        t = Atn(x(i)) + b
    End If

    f = t ^ 2 + Sin(x(i)) ^ 2

    p = f + Sqr(18.45) * Sin(c) + t

    b = (Log(x(i)) ^ 2 + d * y) / (Sin(c) + Cos(d))

    MsgBox "x(" & i & ")=" & x(i) & Chr(10) & Chr(10) & "t = " & t & Chr(10) & "p = " & p & Chr(10) & "f = " & f & Chr(10) & "b = " & b
Next i
End Sub