Question

How do you differentiate `s=(t^2-1)(t^2+1)`?

Answer 1

`4 t^3`

Explanation:

First you open the bracket and multiply the two terms,

`s=(t^2-1)(t^2+1)`
`s= t^4 + t^2 - t^2 - 1`
`s = t^4 - 1`

Now, differentiate for t.

`(ds)/(dt)` = `4 * t ^ (4-1) - 0` = `4 t^3`