Answer:
[tex]f(x) = 4 {x}^{2} - 2 \\ f(t + 1) = 4 {(t + 1)}^{2} - 2 \\ = 4( t + 1)(t + 1) - 2 \\ = 4( {t}^{2} + 2t + 1) - 2 \\ = 4 {t}^{2} + 8t + 4 - 2 \\ = 4 {t}^{2} + 8t + 2[/tex]
I hope I helped you^_^