grapes
The 16th century Italian mathematician, Gerolamo Cardano was the first to use imaginary and complex numbers in his work on cubic equations.
It's nice and simple, just iSo for example (-4)1/2is 2i or -2iAccording to my calculations, (-2)^.5 eq. 1.414i or -1.414iElectrical engineers often use j to represent the imaginary unit, rather than i. This is to avoid confusion with the symbol for electric current, which is I.
Well first you type in the numbers you need then you type in the symbol you need.
Physics (e.g., quantum mechanics, relativity, other subfields) makes use of imaginary numbers. "Complex analysis" (i.e., calculus that includes imaginary numbers) can also be used to evaluate difficult integrals and to perform other mathematical tricks. Engineering, especially Electrical Engineering makes use of complex and imaginary numbers to simplify analysis of some circuits and waveforms.
what symbol do you use when you automatically want to add a set of numbers together? the plus symbol + ?
There is no specific symbol. The symbol for real numbers is R and that for rational numbers is Q so you could use R \ Q.
The symbol is "..."
The first person to write about them was Gerolamo Cardano in 1545, but he doesn't seem to have taken them seriously. See http://en.wikipedia.org/wiki/Gerolamo_Cardano . The first serious use of imaginary numbers (better, complex numbers) was by Rafael Bombelli, published in 1572. He used them as intermediate steps when solving cubic equations. See related link.
# that's what i always use
In common use, yes.so 0.25, 3.156 are real.But it's possible to have decimal imaginary values, and decimal complex values. These are common in (for example) alternating current electrical circuits.The symbol i represents the square root of -1, commonly written as j in electrical calculation.Thus we get 0.25i, 3.156i (imaginary numbers)and2-0.25i, 6.3+3.156i (complex numbers).
The imaginary axis is used in the definition of the complex numbers. Complex numbers are used in many fields in engineering, in particular - electric engineering, aerodynamics, acoustics etc.