Thank you Chip,
Thank you David,
I overlooked my formulation, cell(D2) should look like
=IF(B2<0,360-DEGREES(ACOS(A2/(A2^2+B2^2)^0.5)),DEGREES(ACOS(A2/(A2^2+B2^2)^0.5)))


"danpt" wrote:

I want to modified ACOS function to display in degrees reflecting to its
quartrant.
Is there another simpler formula to replace then one I have in cell(D2)?
Sub worksample()
Range("A1") = "X"
Range("B1") = "Y"
Range("C1") = "deg"
Range("D1") = "mod. ACOS"
Range("A2") = -1
Range("B2") = -1
Range("C2") = "=DEGREES(ACOS(A2/(A2^2+B2^2)^0.5))"
Range("D2") =
"=MOD(IF(B2=0,360,IF(A20,270,IF(A2<0,90,180)))+D EGREES(ACOS(A2/(A2^2+B2^2)^0.5)),360)"
End Sub