TI Tips
COMPLEX:  The '85  has a built in complex number type. In the rectangular form  (a,b)  that represents the complex number a+bi where a and  b are real numbers and i is the imaginary unit whose square is  -1.  Complex numbers can also be represented in polar form as (r,ß) where r is the modulus and ß is the angle.  Complex numbers can be added, multiplied, etc. like real numbers and there are some additional operations: conj gives the conjugate; real gives the real part; imag gives the imaginary part; abs gives the modulus; angle gives the angle.