# square root of a complex number

• Aug 4th 2011, 04:45 AM
hunterage2000
square root of a complex number
Can someone tell me why my calculator is returning a maths error when I try to find the square root of a complex number and how I do it?
• Aug 4th 2011, 04:50 AM
Siron
Re: square root of a complex number
Have you entered the right mode (I think on the ti-83 it was: 'a+bi', in stead of 'real')?
Can you give this complex number.
• Aug 4th 2011, 04:55 AM
bibhukalyana
Re: square root of a complex number

• Aug 4th 2011, 04:57 AM
hunterage2000
Re: square root of a complex number
yeah its in complex mode and the number is 0.1858 + 0.9802i divide by 4.5239x10^-6i
• Aug 4th 2011, 05:13 AM
Siron
Re: square root of a complex number
Did you use for the - sign in the exponent the: operation - (from the difference), or the sign - (to indicate a negative number)? Because that's often a problem. Now, you have to take the 'sign' -.

Do you have to take the square root or just divide the two complex numbers?
• Aug 4th 2011, 05:22 AM
hunterage2000
Re: square root of a complex number
yeah as in 0.0000045239i. Not sure what the problem is, in the book I've got it shows the equation as Z = the square root of z/y were z and y are complex or polar numbers. It doesnt show anything else.
• Aug 4th 2011, 05:35 AM
Bacterius
Re: square root of a complex number
Most calculators only have very limited support for complex numbers. For instance the graphical one on my desk right now cannot even perform exponentiation of complex numbers at all, and hence cannot calculate the square root of a complex number.
Also, did you put brackets when evaluating 4.5239x10^-6i? If you didn't it's quite possible the calculator understood 4.5239x10^(-6i), not 4.5239x10^(-6) i, and your calculator most likely cannot evaluate complex exponentiation hence math error.
• Aug 4th 2011, 06:08 AM
skeeter
Re: square root of a complex number
you still haven't stated what calculator you are using.

my TI-84 does this operation fine in classic mode ... will not do it using the "pretty print" mode.

the entire output (not shown in the screen shot) is

467.5473811-43.92149245i
• Aug 4th 2011, 06:26 AM
hunterage2000
Re: square root of a complex number
yeah sorry Skeeter its a Casio fx-991ES PLUS
• Aug 4th 2011, 06:46 AM
skeeter
Re: square root of a complex number
Quote:

Originally Posted by hunterage2000
yeah sorry Skeeter its a Casio fx-991ES PLUS

Sorry, but I'm not familiar with the operations of Casio calculators. I recommend you try a web search and/or wait for someone here w/ Casio knowledge that maybe can help.
• Nov 6th 2011, 08:02 AM
sbhatnagar
Re: square root of a complex number
Wolfram alpha or mathematica can also be used for such operations.