Thread: Complex no clarifications

Hi I have a few more doubts!

How do I get from -(±(3-2i))^2 to (3i+2)^2?

I know the - sign in front is i^2, so I multiply it in..but if I multiply i^2 in isn't it (3i^2-2i^3)^2 instead, thus (-3+2i)^2?

Also, is |a-bi| = a+bi?

Thank you so so much!

and

Originally Posted by Tutu

Hi I have a few more doubts!

How do I get from -(±(3-2i))^2 to (3i+2)^2?

I know the - sign in front is i^2, so I multiply it in..but if I multiply i^2 in isn't it (3i^2-2i^3)^2 instead, thus (-3+2i)^2?

Also, is |a-bi| = a+bi?

Thank you so so much!

Surely you know that | | is a non-negative real number? So "|a- bi|= a+ bi" is automatically impossible. It possible that you meant to ask if |a- bi|= |a+ bi|. The answer to that is certainly yes: .