If you multiply two imaginary numbers

[Tonyator]

I kind of understand it, I should though, I did Maths and Further Maths for A level....

 

[Ricochet J]

what is an imaginary number?

The roots of a negative number.

We know the square root of 9 is 3 or -3 (as in multiply 3 or -3 by itself and you get 9). But what are the roots of -9? No real integers multiply itself together to give -9. Hence we say 3 multiplied by itself multiplied by j gives -9 where j is a complx/imaginary notation.

 

[Jonny69]

More of a general engineering notation as far as I'm aware?

Mech Eng at Brunel used i, but then we were taught maths by the maths dept bods

 

[TommyTenToes]

Mech Eng at Brunel used i, but then we were taught maths by the maths dept bods

Yeah Mech Eng at Edinburgh used i when doing the core maths modules, then switched to j once it started to be incorporated in the engineering modules.

 

[V4NT0M]

Planes fly over my house all the time but really never have I witnessed such a woosh.