Subconvexity bound for $GL(2)$ L-functions: \lowercase{t}-aspect

Let $f$ be a holomorphic Hecke eigenform or a Hecke-Maass cusp form for the full modular group $SL(2, \mathbb{Z})$. In this paper we shall use circle method to prove the Weyl exponent for $GL(2)$ $L$-functions. We shall prove that $$L \left( \frac{1}{2} + it, f \right) \ll_{f, \epsilon} \left( 2 + |t|\right)^{1/3 + \epsilon},$$ for any $\epsilon > 0.$