1. Federal University of Pará, Raimundo Santana Street, s/n, 68721-000 Salinópolis, PA, Brazil
2. Ph.D. Program in Mathematics, Federal University of Pará, Augusto Corrêa Street, 01, 66075-110 Belém, PA, Brazil
3. Universidade Zambeze-Faculdade de Ciências e Tecnologia, Av. Alfredo Lawley, n 1018, Matacuane, Beira/Sofala, Mozambique
4. Faculty of Exact Sciences and Technology, Federal University of Pará, Manoel de Abre Street, s/n, 68440-000 Abaetetuba, PA, Brazil