Question

solve by substituting a variable to simplify the equation: x^4+2x^2=8
How do i get the answer; + or - the square root of 2 and + or - 2i

Answer 1

use the substitution k = x^2

Answer 2

\[x^4+2x^2-8=0\]
\[u=x^2\]
\[u^2+2u-8=0\\]

Answer 3

how do i get the answer; + or - the square root of 2 and + or - 2i