How to Find Instantaneous Velocity at a Specific Time?

[[Nicolette]]

Homework Statement

Find the instantaneous velocity at t=1 by computing v(1)= [h(1+$$\Delta$$t)-h(1)]/$$\Delta$$t

I found that v(1)= -8ft/sec. Also I know h(1)=24 but i don't understand how to manipulate the h(1+$$\Delta$$t) to get the solution.

Homework Equations

h(t)=16+24t-16t²

The Attempt at a Solution

The solution the teacher gave is v(1)=-8-16t$$\Delta$$

 

[rootX]

What's h(1+dt)? Substitute (1+dt) into the h(t) equation.. and put everything in the v(1)= [h(1+dt)-h(1)]/dt equation. If you expand the equation and do some algebra you will eventually get the answer