Question

(x^2+1)^2-(x^2-1)-4x^2​

Answer 1

Step-by-step explanation:

Let x^2+1 = y or x^2 = y - 1 (y>1)

New equation will be

${y}^{2} - (y - 1 - 1) - 4(y - 1) = 0 \\\implies {y }^{2} - 5y + 6 = 0 \\ \implies \: y = 2 \: and \: 3 \\ \implies \: {x}^{2} = 1 \: and \: 2 \\ \implies \: |x| = 1 \: and \: \sqrt{2}$

so x = 1 , -1 , √2 and -√2