Heres the equation:
x^-8 - 17x^-4 + 16 = 0
The book asks me to use U-Substitution, so here is my work:
u = x^-4 (u-substitution)
u^2 - 17u + 16 = 0
(u - 1) (u - 16) = 0
u = 1 u = 16
x^-4 = 1 x^-4 = 16
This is where I get stuck. I know that x = +/- 1 and x = +/- 1/2.
But the back of my book also says that x = +/- i and x = +/- 1/2i.
I don't understand where these imaginary numbers are coming from?
x^-8 - 17x^-4 + 16 = 0
The book asks me to use U-Substitution, so here is my work:
u = x^-4 (u-substitution)
u^2 - 17u + 16 = 0
(u - 1) (u - 16) = 0
u = 1 u = 16
x^-4 = 1 x^-4 = 16
This is where I get stuck. I know that x = +/- 1 and x = +/- 1/2.
But the back of my book also says that x = +/- i and x = +/- 1/2i.
I don't understand where these imaginary numbers are coming from?