“…For example, it is well known that the spectrum of an operator is contained in the closure of its numerical range. For basic properties numerical radius, we refer to (Alomari, 2021), (Aici et al, 2023), (Bhunia and Paul, 2021), , (Dragomir, 2009), (Gustanson and Rao, 1997), (Jana et al, 2023), (Kian, 2014), (Kian and Alomari, 2022), (Qawasmeh et al, 2023).…”