 |
| ||
| |||
|
| Math Central | Quandaries & Queries |
|
Question from Diana, a student: Perform the operation. Write all answers in a + bi form. -12 |
Diana,
What you have to see here is that if √(-1) = i then
(7 - i)(7 + i) = 72 - 1 = 48
If this is something you don't know then expand (7 - i)(7 + i) and simplify.
Hence in your problem if you multiply the numerator and denominator by 7 + i then the denominator becomes 48.
Penny
| ||
| ||
| ||
 |
 |
|
Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.