PLEASE HELP!!! MEDAL WILL BE REWARDED!!!!!
The position of an object at time t is given by s(t) = -4 - 2t. Find the instantaneous velocity at t = 6 by finding the derivative.

Question

PLEASE HELP!!! MEDAL WILL BE REWARDED!!!!!
The position of an object at time t is given by s(t) = -4 - 2t. Find the instantaneous velocity at t = 6 by finding the derivative.

austinl · Answer

This problem is just like the last one. We need to find the derivative of s(t), then plug in the given value for time.

anonymous · Answer

Okay, so would it be -8? t=-8? but that's not the velocity is it?

anonymous · Answer

oh no wait -16

austinl · Answer

$$s(t) = -4 - 2t$$
Wait... did you copy this down correctly?

anonymous · Answer

Yes

austinl · Answer

Well, when you take the derivative of s(t), it is 0... are you sure?

anonymous · Answer

yes that is exactly how the question states it

austinl · Answer

Hmm... well is it multiple choice?

anonymous · Answer

no this one unfortunately is an essay question(do it yourself kinda problem)

anonymous · Answer

That's why im confused

austinl · Answer

Well, based on what I have seen... I would have to say the instantaneous velocity at t=6 has to be zero.
$$s(t) = - 4 -2t$$
$$s^{\prime}(t) = 0$$
So, in the derivative there is no t to place the given value into...

austinl · Answer

Excuse me,
$$s^{\prime}(t) = -2$$

austinl · Answer

So, -2 for an instantaneous velocity?

anonymous · Answer

okay, I will put that I guess, thank you so much for your help! also, do you know much about finding limits from looking a graph? Multiple choice...

austinl · Answer

The way that this problem is set up is kinda silly.

austinl · Answer

From a graph? Sure, I can take a crack at it. Post another question.

anonymous · Answer

Okay thanks I will now