Z Zfuss12 New member Joined Oct 13, 2005 Messages 29 Oct 25, 2005 #1 How would you show that the product of a+bi and its conjugate is a real number? I did this: (a+bi)(a-bi)=a^2-abi+abi-bi^2=a^2+b but im not sure if this is right...or what eaxactly it proves and how HELP PLEASE...!?
How would you show that the product of a+bi and its conjugate is a real number? I did this: (a+bi)(a-bi)=a^2-abi+abi-bi^2=a^2+b but im not sure if this is right...or what eaxactly it proves and how HELP PLEASE...!?
U Unco Senior Member Joined Jul 21, 2005 Messages 1,134 Oct 25, 2005 #2 Almost! You've just forgotten to square the b!
Z Zfuss12 New member Joined Oct 13, 2005 Messages 29 Oct 25, 2005 #3 but how does that prove its a real number?
U Unco Senior Member Joined Jul 21, 2005 Messages 1,134 Oct 25, 2005 #4 There is no imaginary component in your result, ie. there are no i's!
