Hello,
Just started calculus. I am fairly comfortable with limit problems in what has been given to us, but I'm thoroughly lost when given a problem like this.
Any help would be appreciated, thanks.
When you replace s(a) and s(t) with $\displaystyle -4.9a^2+200$ and $\displaystyle -4.9t^2+200$, you get a lot of cancellation. Remember the identity $\displaystyle x^2-y^2=(x+y)(x-y)$.
They're getting you ready for derivatives - the limit you are calculating is just the derivative of s(t) at a.
- Hollywood