Proof: 1 = t(1 + t²) = a

Here is a formula I came across that I had equated together; but I was wondering how I came to the conclusion that I did.[br][br]1) So here is one way of doing it.
Proof: 1 = t(1 + t²) = a
– RV'SMath

Information: Proof: 1 = t(1 + t²) = a