Hi... in my workpage display its.

acos(0.1)=1.4706
acos(0.11)=1.4606+1.1102*10^-16*i
acos(0.12)=1.4505

wait?
thanks.
Lucio

Hello Lucio,

SMath does not have the treshold of the real and imaginary numbers. That means that there is not incorporated the procedure for presenting small real and imaginary numbers. Therefore, in some cases SMath will represent a complex number with rather small imaginary part instead of a real number expected. The small imaginary part (like in your case) is often due to the small numerical error of the numerical algorithm applied.

For instance, it is rational to represent a small real number say, 10^-35 as zero, or a comples number, say 5.3+1.8*10^(-18) as 5.3 ignoring the imaginary part. This is not implemented in SMath yet.

Regards,
Radovan