Question

x^4 - 4 = 0
How do you solve?

Answer 1

factorise
using a^2-b^2=(a+b)(a-b)

Answer 2

whats A and B? 1 and -4?

Answer 3

x^4 - 4 = 0
(x^2)^2 -2^2=0
(x^2-2)(x^2+2)=0
(x+sqrt(2))(x-sqrt(2))(x+isqrt(2))(x-isqrt(2))=0
hence x=+sqrt(2), -sqrt(2) ,+i*sqrt(2), -i*sqrt(2)

Answer 4

a---> x^2 and b-->2

Answer 5

OHH yeah! thanks, i think i remember now