x^4 - 2x^2 + 1 = 0
let u = x^2
u^2 - 2u + 1
(u-1)(u-1)
Sub in x^2 in u
(x^2-1)(x^2-1)
(x-1)(x+1)(x-1)(x+1)
so solutions are x=1 and x=-1
let u = x^2
u^2 - 2u + 1
(u-1)(u-1)
Sub in x^2 in u
(x^2-1)(x^2-1)
(x-1)(x+1)(x-1)(x+1)
so solutions are x=1 and x=-1
Statistics : Posted by bhavik29 • on 16 Sep 2014, 00:20 • Replies 11 • Views 43405