# How do you find the complex roots of #a^2-81=0#?

##### 1 Answer

Nov 27, 2016

#### Answer:

This quadratic has only two Real roots.

#### Explanation:

This can be factored as a difference of squares, or

#a^2-81=0#

#a^2-9^2=0#

#(a+9)(a-9)=0#

So the two solutions, both of which are Real, are