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1.1.5 Complex Numbers

You can enter complex numbers in Mathematica just by including the constant I, equal to . Make sure that you type a capital I.

If you are using notebooks, you can also enter I as by typing EscapeKeyiiEscapeKey (see Section 1.1.7). The form is normally what is used in output. Note that an ordinary i means a variable named , not .

This gives the imaginary number result .

In[1]:= Sqrt[-4]


This gives the ratio of two complex numbers.

In[2]:= (4 + 3 I) / (2 - I)


Here is the numerical value of a complex exponential.

In[3]:= Exp[2 + 9 I] //N


Complex number operations.