Question

What is the form of the Difference of Cubes indentity?

Answer 1

The difference of cubes identity is

if a and b are any two real numbers, then difference of their cubes, when taken individually:

a³-b³= (a-b)(a² + ab + b²)→→→Option (D) is

true option.

I will show you, how this identity is valid.

Taking RHS

(a-b)(a² +b²+ab)

= a (a² +b²+ab)-b(a² +b²+ab)

= a³ + a b² +a²b -b a² -b³-ab² Cancelling like terms, we get

= a³-b³

= LHS