Question

f(x) = x^4 - x^2 - 30

Answer 1

let x^2=a

0=a^2-a-30
(a-.5)^2=30 + .25
a-.5= +-5.5
a=.5+-5.5
a= -5 , 6

Answer 2

so
x^2=6
x= +-sqrt6
x^2=-5
x= +-isqrt5

Answer 3

\[\sqrt{6},~~~~-\sqrt{6},~~~~i \sqrt {5},~~~~-i \sqrt {5}\]

Answer 4

Wouldn't that just become x^2-30?

Answer 5

no, it would be a^2-a-30

Answer 6

Where are you getting that a from? o.O