The IMSEC function returns the secant of a complex number in x+yi or x+yj text format.

  • This function was introduced in Excel 2013 and so is not available in earlier versions.




Argument Description
inumber A complex number for which you want the secant

Note: Use the COMPLEX function to convert real and imaginary coefficients into a complex number.


  A B C D
1 Data Formula Result Notes
2 3+4i =IMSEC(A2) -0.0362534969158689+0.00516434460775318i Returns the secant of a complex number, 3+4i
3   =IMSEC(“3+4i”) -0.0362534969158689+0.00516434460775318i  
4   =IMSEC(“2-i”) -0.41314934426694-0.687527438655479i  
5   =IMSEC(COMPLEX(4,1)) -0.557760402867351-0.491827502294509i  

Common Function Error(s)

Problem What went wrong
#VALUE! Occurs if the supplied inumber argument is a logical value
#NUM! Occurs if the supplied inumber argument is not recognized as a complex number

The secant of a complex number is defined as the inverse of the cosine and is calculated as:  

    \[  secant(z) = \frac{1}{cosine(z)}   \]

See Wikipedia for more information on complex numbers.