Question

How did we get t^4/4 to t^3?

Answer 1

looks like differentiation. without going into the reasons why, when you differentiate a term in the form

`a * {x}^(b)`
it turns into

`a * \frac{ {x}^(b - 1) }{b}`
as a hint you could rewrite the original term as

`(1)/(4) * {t}^(4)`