The position of an object at time t is given by s(t) = -9 - 3t. Find the instantaneous velocity at t = 8 by finding the derivative.
@e.mccormick @jim_thompson5910
would this sort of be like the other ones? the same process?

Question

The position of an object at time t is given by s(t) = -9 - 3t. Find the instantaneous velocity at t = 8 by finding the derivative.
@e.mccormick @jim_thompson5910 
would this sort of be like the other ones? the same process?

e.mccormick · Answer

Yes.  Instant velocity is found using the derivative.

anonymous · Answer

i got -3

e.mccormick · Answer

Yes.  When there is no power, it is pretty easy that way.

anonymous · Answer

so thats it? or

anonymous · Answer

@e.mccormick

e.mccormick · Answer

That is it.

anonymous · Answer

what about the whole t=8 part so i ignore it?

e.mccormick · Answer

It has a constant velocity, so it is the same at any point.

anonymous · Answer

so if i turn this is i will be correct: d/dx(-9-3x)=-3
-d/dx(9)-d/dx(3x)
d/dx=(9)=0
d/dx(3x0=3
=0-3
=-3

e.mccormick · Answer

If it was $s(t) = -9 - 3t^2$ then the velocity would be changing and there would be more to do.  But for $s(t) = -9 - 3t$  it is just -3.

e.mccormick · Answer

Yah.

anonymous · Answer

thank you c: