How do you multiply/divide complex numbers in Excel?

AI Thread Summary
The discussion revolves around calculating complex numbers in Excel, specifically the expression (.462-.32094i)*[(7.2+9.6i)/(4-8i)], which yields the result .107+.748i. Users seek guidance on how to dynamically enter varying values in Excel while obtaining updated results. The recommended formula for this operation is =IMPRODUCT(COMPLEX(0.462,-0.32094),IMDIV(COMPLEX(7.2,9.6),COMPLEX(4,-8)). It is also suggested to enable Excel's Analysis ToolPak for complex number functions. Alternative methods for handling complex numbers, such as converting between rectangular and polar coordinates, are discussed but deemed less practical given Excel's capabilities. Additionally, there is a clarification that the original expression is not an equation due to the absence of an equals sign. The importance of checking post dates in forum discussions is also mentioned, highlighting the need for up-to-date information.
camino
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I have the equation:

(.462-.32094i)*[(7.2+9.6i)/(4-8i)]

the answer is:

.107+.748i

Now, I need to know how to enter this in Excel, because the 4 will be varying and I will need many rows and then my answer to be changing with the change in the equation.

I have tried =COMPLEX(.462,-.32094)*(COMPLEX(7.2,9.6)/COMPLEX(4,-8)) but this does not work.

Please help!
 
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This isn't a direct answer, but you will be much better served now AND in the future by simply using real mathematical software. Mathematica, Matlab, Maple, etc...
 
See the Excel "Engineering" functions "IMPRODUCT", IMDIV", "IMSUB", "IMSUM", etc.
 
Here's how I'd do it...

Enter your varying number in the yellow box, your result will be displayed in the green box.
 

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Try this:

=IMPRODUCT(COMPLEX(0.462,-0.32094),IMDIV(COMPLEX(7.2,9.6),COMPLEX(4,-8)))
 
To get the complex functions you need to go to Tools->Add ins and select the Analysis Pac to install.
 
You could also do this the old fashioned way.

Convert your number from rectangular coordinates to polar coordinates using the Pythagorean Theorem and arctangent.

Divide the magnitude as normal while subtracting the angles (best to leave it in radians).

Multiply the magnitude as normal while adding the angles.

Take powers and roots for the magnitude as normal. Multiply or divide your angle (depending on whether you're calculating a power or a root).

Convert your final answer back to rectangular coordinates using cosine and sine.

Not a whole lot of reason when Excel handles complex numbers. But it does work, especially if you're using a slide rule or a calculator that doesn't handle complex numbers.
 
BobG said:
If God meant for man to count higher than 1,048,575 he would have given him more fingers and toes.

Technically, you could count to 1,048,576 using 20 digits (fingers and toes).

Consider that with 2 digits, you can count from 0 to 3; that's 4 possible outcomes, therefore you can count 4 things with 2 digits. The 1st item is 00, the 2nd item is 01, the 3rd is 10 and the 4th is 11. (Zero items gets no label at all).

I'm just saying...
 
camino said:
I have the equation:

(.462-.32094i)*[(7.2+9.6i)/(4-8i)]

the answer is:

.107+.748i
Not a big point, but this -- (.462-.32094i)*[(7.2+9.6i)/(4-8i)] -- is not an equation. A major clue is the absence of an equals sign.
 
  • #10
Mark44 said:
Not a big point, but this -- (.462-.32094i)*[(7.2+9.6i)/(4-8i)] -- is not an equation. A major clue is the absence of an equals sign.

True in both points (it's not an equation and it's not a big point).

The OP should have said, "I have the expression..."
 
  • #11
your right man
 
  • #12
"=improduct(...,imdiv(...,...))"
... this cell is complex numbers.
 
  • #13
Two people already posted this answer (posts 3 and 5), more than a year and a half ago.

Some advice: when you find a thread via a Google search or something, check the dates on the posts before you respond.
 
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