Purpose

Return value

Syntax

=IMSIN(complex_num)
  • complex_num - The complex number in the form “x+yi”.

Using the IMSIN function

The Excel IMSIN function returns the sine of a complex number. For instance, given “1+1i” as input, the function returns the complex number equal to the sine of the input.

=IMSIN("1+1i") // returns 1.29845758141598+0.634963914784736i

Given real number input, the function behaves like the sine function. For example, given π + 0i as input the function returns 3.23108914886517E-15 (approximately zero). The sine of π is zero, but due to floating-point precision, it returns a very small number close to zero.

=IMSIN(COMPLEX(PI(),0)) // returns 3.23108914886517E-15

Explanation

Mathematically, the sine of a complex number can be represented using a combination of the standard and hyperbolic trigonometric functions.

Definition of sine for a complex number. - 1

If B6 contains a complex number in the form “x+yi”, this is equivalent to the following formula.

=COMPLEX(
    SIN(IMREAL(B6))*COSH(IMAGINARY(B6)),
    COS(IMREAL(B6))*SINH(IMAGINARY(B6))
)

Alternatively, the sine of a complex number can be defined in terms of the exponential function, where “z=x+yi”.

Sine of a complex number in terms of the exponential function. - 2

If B6 contains a complex number in the form “x+yi”, this is equivalent to the following formula.

=IMDIV(
    IMSUB(
        IMEXP(IMPRODUCT(COMPLEX(0,1), B6)), 
        IMEXP(IMPRODUCT(COMPLEX(0,-1), B6))
    ),
    COMPLEX(0, 2)
)

Purpose

Return value

Syntax

=IMSINH(complex_num)
  • complex_num - The complex number in the form “x+yi”.

Using the IMSINH function

The Excel IMSINH function returns the hyperbolic sine of a complex number. For example, given 1+π/2i as input, the function returns -4.10319E-15 + 1.543080635i as output.

=IMSINH(COMPLEX(1, PI()/2)) // returns -4.10319E-15 + 1.543080635i

When the function’s output is plotted over the complex plane, the real output along the real axis traces the shape of the SINH function .

=IMSINH(COMPLEX(x,0)) // returns SINH(x) + 0i

The imaginary output along the imaginary axis traces the shape of the SIN function .

=IMSINH(COMPLEX(0,y)) // returns 0 + SIN(y)i

Explanation

The function can be defined for complex input using the SIN , COS , SINH , and COSH functions, which take real numbers as input.

IMSINH function definition. - 3