What are imaginary numbers?
Imaginary numbers are any numbers that include the imaginary number i. A mix of imaginary and real numbers gives you what’s called a complex number.
The primary reason we use imaginary numbers is to give us a way to find the root (radical) of a negative number. There’s no way to use real numbers to find the root of a negative number, which prevents us from solving even simple polynomial equations.
But with imaginary numbers, we define the square root of -1 as the imaginary number i, and that allows us to easily find the roots of imaginary numbers.
0:21 Are imaginary numbers real numbers?
0:45 Examples of real and imaginary numbers
1:22 The definition of the imaginary number i
1:39 Why do we need imaginary numbers?
1:53 Why is the imaginary number helpful?
2:52 What happens when you square the imaginary number?
Ready to start winning at math?
Our math courses will be the exact fix you’ve been so desperate for to help you pass your class so you can get on with your education, finish your degree with less stress, and have the career you’re dreaming of.