Euler named a number i (iota), this is defined as imaginary unit.
With the help of i we can interpret the square root of a negative number
i^2=-1 or root of -1=i
any number which can be expressed in the form a+bi where a and b are real number and i=root of -1 is complex number
Conjugate of a complex number z=a+bi is z=a-bi.
z1 +z2 = (a1+a2)+(b1+b2)i
addition of two comlex numbers
z1-z2=(a1-a2)+(b1-b2)i
subtraction of two complex numbers
multiplication of complex numbers
z1z2=(a1a2-b1b2)+(a1b2+a2b1)i
IzI=I a+bi I = square root of a^2+b^2
