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Engineering function

IMLN

Returns the natural logarithm of a complex number.

Rarely usedDifficulty 1500 · AdvancedUsage rank #495 of 520
Practice · 2 questions →

When to use it

The natural logarithm of a complex number, using the principal branch.

The shape of it

Syntax
=IMLN(inumber)

Worked examples

  • Typical

    =IMLN("3+4i") → 1.6094379124341+0.927295218001612i

    LN of the modulus plus i times the argument.

  • One

    =IMLN("1") → 0

    LN of one.

  • Pure imaginary

    =IMLN("i") → 1.5707963267949i

    i pi over two.

Worth knowing

  • Real part is LN(IMABS), imaginary part is IMARGUMENT.
  • IMEXP is the inverse.
  • The imaginary part is between -pi and pi.

Where it goes wrong

  • #NUM! for "0".
  • #VALUE! for invalid text.

Related

CONVERTBIN2DECDEC2BINHEX2DECDEC2HEXDELTA

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