Since the form is indeterminant

Method 1: factorization

Since a³ + b³ = (a + b)(a² + b²-ab) & a²-b² = (a + b)(a-b)

= 2a + 0

= 2a

Method 2: By L hospital rule:

Differentiating numerator and denominator separately:

= 2(a + 0)

= 2a