Question

Factor of (D2 + a2) = 0

Answer 1

hey mate

(a² - b²)(c² - d²) - 4abcd = a²c² - a²d² - b²c² + b²d² - 2abcd - 2abcd

=a²c² + b²d² - 2abcd - { a²d² + b²c² - 2abcd } = (ac-bd)² - (ad- bc)²

= (ac-bd - ad + bc) (ac -bd + ad -bc)           [ p² - q² = (p-q)(p+q) ]