Справка LibreOffice 7.4
Returns the secant of a complex number. The secant of a complex number can be expressed by:
МНИМ.SEC(КомплексноеЧисло)
Complex_number is a complex number whose secant needs to be calculated.
=МНИМ.SEC("4-3i")
возвращает -0,0652940278579471+0,0752249603027732i.
=IMSEC(2)
returns -2.40299796172238 as a string. The imaginary part is equal to zero, so it is not displayed in the result.