Question

factorise the above​

Answer 1

${a}^{4} - b {}^{4} + 2b {}^{2} - 1$

${a}^{4} - ( {b}^{4} - 2 {b}^{2} + 1)$

Using Identity (a-b)^2

${a}^{4} - ( {b}^{2} - 1) {}^{2}$

Using Identity a^2- b^2

$(a {}^{2} - ( {b}^{2} - 1))(a {}^{2} + ( {b}^{2} - 1)$

$({a}^{2} - {b}^{2} + 1)( {a}^{2} + {b}^{2} - 1)$

Hope it helps you.........