Question

x^4-x^2-2

Answer 1

first do y^2 - y -2

Answer 2

then replace y by x^2

Answer 3

\[(x ^{2})^{2}-x ^{2}-2=0\]
\[x ^{2}=a\]
\[a ^{2}-a-2=0\]

(a-2)(a+1)=0
\[a _{1}=2\]
\[a _{2}=-1\]
\[x ^{2}=2\]
\[x _{1}=\sqrt{2}\]
\[x _{2}=-\sqrt{2}\]
\[x ^{2}=-1\]
\[x _{3}=i\]
\[x _{4}=-i\]