Question

$a ^{4} - 2a ^{2}b ^{2} + b ^{4}$
Factorise​

Answer 1

Without using identity

a⁴ - 2a²b² + b⁴

a⁴ - a²b² - a²b² + b⁴

a²(a² - b²) - a²(a² - b²)

(a² - b²)²

Using Identity (x - y)² = x² + y² - 2xy

a⁴ - 2a²b² + b⁴

(a²)² - 2*a²*b² + (b²)²

(a² - b²)²