Transcript MTH 100 Complex Numbers

MTH 100
Complex Numbers
Introducing The Imaginary Number i
• We use i to simplify square roots when the
radicand is negative:
i  1
Examples
 147
 16  4
 5   45
Using i Algebraically
1. Treat i like a regular variable, until it is
squared. Then change i2 to -1.
2. A number written in complex number form is
written as a + bi.
3. When dividing complex numbers, use the
conjugate of the denominator.
Examples
6  5i    8  9i  8i  8i
3  2i    6  8i   2i 2  5i 
4  6i 5  i 
5i
5  2i