Table 13 \(L^{2}\)-norm and convergence rate when \(\beta =\gamma =0.3,0.5, 0.8\) and \(\tau =h\)

1/2⁴

1.5804e−05

–

1.4156e−05

–

1.2805e−05

–

1/2⁵

4.2150e−06

1.9067

3.8236e−06

1.8884

3.5015e−06

1.8707

1/2⁶

1.0833e−06

1.9601

9.9123e−07

1.9476

9.1644e−07

1.9339

1/2⁷

2.7406e−07

1.9829

2.5219e−07

1.9747

2.3463e−07

1.9657

1/2⁸

6.8920e−08

1.9915

6.3652e−08

1.9862

5.9574e−08

1.9776