How to factor the fourth degree polynomial $$ x^4+x^2+2ax+1-a^2 $$

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Uniteasy Admin · Accepted Answer

Group the terms to form perfect squares 
$$ x^4+x^2+2ax+1-a^2 $$ 
$$ x^4+2x^2+1-x^2+2ax-a^2 $$
$$ (x^2+1)^2-(x-a)^2 $$
Now use the formula for difference of squares
$$ (x^2+x-a+1)(x^2-x+a+1) $$

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