Given the following function:
[tex]f(x)=2x^2-1[/tex]to find f(2n), we have to make x = 2n, and then simplify the resulting expression when we evaluate 2n inside the function:
[tex]\begin{gathered} x=2n \\ \Rightarrow f(2n)=2(2n)^2-1=2(4n^2)-1=8n^2-1 \\ f(2n)=8n^2-1 \end{gathered}[/tex]therefore, f(2n) = 8n^2 - 1
