Question

Need a little help--Instantaneous velocity: (derivatives) s=8t(squared)-10t+6; t=5. any help?,Thanks

Answer 1

Just use the sum rule. The derivative of a sum is the sum of the derivatives of each term.

Answer 2

s'=2*8t-10
s'(5)=16(5)-10

Answer 3

so s=156?

Answer 4

No, s'(5) = 156

Answer 5

s'(5)=80-10=70
did i miss something?

Answer 6

yeah, it's 70

Answer 7

I didn't check his arithmetic. In anycase, this is the trouble with just solving people's problems myininaya. They don't understand what you did, so they don't understand the answer, or how to do it again next time.

Answer 8

can you take it step by step for me ? now I am missing something , Thanks

Answer 9

do you know how to find the derivative?

Answer 10

yes

Answer 11

what is s' = then?

Answer 12

Prime

Answer 13

what is s'=______________?

Answer 14

oh - i got 156

Answer 15

the derivative of 8t^2 is?
the derivative of 10t is?
the derivative of constant is?

Answer 16

no clown i'm asking what is s'
not what s' at some number is

Answer 17

16t,10,0

Answer 18

so s'=16t+10+0=16t+10

Answer 19

oops s'=16t-10 i forgot the minus in the problem

Answer 20

so what is s' at t=5

Answer 21

Man your rough! but you make me think! ---- Thanks

Answer 22

i'm rough lol

Answer 23

do you get 70 now?

Answer 24

Hold on Im old!

Answer 25

yes, Thank you , Wow ! LOL

Answer 26

you really got it?
ok what's the instanteous velocity of s=t^4-6^2+3 at t=3

Answer 27

Oh and by the way I am a real clown, A Shriner Clown

Answer 28

s=t^4-6t^2+3

Answer 29

cool. lol

Answer 30

s=45?

Answer 31

what is s' ?

Answer 32

um, ok im lost ! Help!!

Answer 33

we want to find the instanteous velocity of s=t^4-6t^2+3 at t=3
finding velocity means we need to find the derivative of s
s' denotes the derivative
first let's break this up
what is the derivative of t^4?
what is the derivative of -6t^2?
what is the derivative of 3?

Answer 34

3t,12t,0

Answer 35

-12t oops

Answer 36

derivative of t^4 is 4*t^3
i used the power rule
everything else you got right
so 2/3 is passing

Answer 37

you funny and yes you are right about the first answer , you are making me think faster than normal! and making me nervous! I do not want to come off to you as a complete rock!

Answer 38

i'm sorry

Answer 39

lol take as much time as you need

Answer 40

ok, Thanks! Just wish sometimes I was better at this stuff, like you- I love smart math people!

Answer 41

clowns are cool too

Answer 42

let's put all the terms of s' together so
s'=?

Answer 43

ok, hold, please

Answer 44

k

Answer 45

s=96

Answer 46

i don't think thats right
and like polak said before its s'(3)=96
tell me what s' is first

Answer 47

s'(t)=

Answer 48

4(3)^3-12+3 Right?

Answer 49

s'(3)=4(3)^3-12(3)

Answer 50

remember we said the derivative of t^4 is 4t^3
the derivative of -6t^2 is -12t
the derivative of 3 is 0

Answer 51

OK!!!!! 3 is prime right?

Answer 52

yes 3 is prime
since 3 is a constant, its slope is zero, and since its slope is zero then the derivative of 3 is zero

Answer 53

we had a- 6t in the original problem? sorry my Bad yes we did, SO SORRY!

Answer 54

Hold on

Answer 55

s= 144+ 3?

Answer 56

or just 144?

Answer 57

ok...so whats our question?

Answer 58

s=t^4-6t^2+3
find velocity at t=3
i think hes getting mixed up on where things go

Answer 59

so clown; you say you can find a derivative; right?

Answer 60

I thought so, guess not

Answer 61

go ahead and give it a shot, i wanna see what you are doing

Answer 62

what is the derivative of:

t^4 -6^t +3 ??

Answer 63

Here is my problem..... s=8t^2 -10t +6; t=5

Answer 64

ok....lets work with 8t^2 -10t +6; what do you think the derivative should look like?

Answer 65

16t- 10 + 6

Answer 66

very close; the first and second terms are good; that last terms should be a 0 tho. do you know why?

Answer 67

because there is no constant?

Answer 68

does 6 = 6 t^0 ? and if so; how would you derive:

6 t^0?

Answer 69

Yes , due to the fact of the power 0

Answer 70

good;

then lets rewrite this in terms you can see :)

8t^2 -10t +6t^0; now derive that for me...

Answer 71

16t-10+6

Answer 72

16t is good;

-10 is excellent.

but 6 is wrong, you didnt derive it the same way you did the others ...why not?

derive 6t^0. in exactly the same way as you did the others. what do we get?

Answer 73

0

Answer 74

that is correct:)

so would you agree that our derivative is then:

16t-10 ?

Answer 75

Yes

Answer 76

ds
-- = 16t-10 very good; now when t=5, what does this equal?
dt

Answer 77

70!! I got it and you did not leave me at the train depot!!! YEA!!!!!

Answer 78

yay!!! :)

Answer 79

Thaank you very much!!!

Answer 80

youre welcome :)

Answer 81

Talk to ya soon maybe