Question

What are the types of roots of the equation below?

x^4 - 81 = 0

Answer 1

x^4-81=0
(x^2+9)(x^2-9)=0
(not real)=0 (x^2-9)=0
(x^2-9)=(x+3)(x-3)
Real roots=-3,3, also irrational -(-9)^(1/2), (-9)^(1/2)