Finding the absolute value (modulus) and solving equation

[infiniteking1]

1. | (2-i)(3+2i)(-5-6i)(-7+3i) / (-4+i) |

Homework Equations

3. I am pretty sure I am not computing it right but this is what i come up with.

square root of 5* square root of 13* square root of 61* square root of 58 / square root of 17.

 

[Dick]

I'm really sure you are computing it right. |a*b|=|a|*|b|, yes? Why do you think it's not right?

 

[infiniteking1]

I'm not sure if the value of i by itself is 1 or whether or not to include it when I am finding the square root.

 

[Dick]

I'm not sure if the value of i by itself is 1 or whether or not to include it when I am finding the square root.

The absolute value of a+bi where a and b are both real is sqrt(a^2+b^2). It's the length of the hypotenuse of the triangle with real side a and imaginary perpendicular side b in the Argand diagram. It's the pythagorean theorem. |1|=1 and |i|=1. You are doing everything correctly. Trust me.

 

[infiniteking1]

Ok, thanks for the help. Making sure but there's nothing more to do to this problem, correct?

 

[Dick]

Ok, thanks for the help. Making sure but there's nothing more to do to this problem, correct?

Not really. You could collect the square roots, or you could write it as an approximate decimal. But I don't see any reason to do that.