Question

what is the derivative of s(t)=-0.001t(t+35)(t-35)

Answer 1

It might be easier to multiply out your expression
(t+35)(t-35) will give a difference of squares.
then multiply by t
(leave the -0.001 out of all this until the very end)

Answer 2

oki @phi so I got t^2-35t+35t-1125
now what

Answer 3

first notice -35t+35t is 0
second 35*35= 1225

now (ignoring the -0.001) you have
t(t^2- 1225)
distribute the t
\[ t^3 -1225t\]

Answer 4

now take the derivative term by term

then multiply everything by -0.001

Answer 5

is it -0.003t^2-1.225

Answer 6

@phi

Answer 7

1.225 shouldn't be negative, otherwise it's correct.
\[s'(t)=-0.003x^2+1.225\]

Answer 8

thankyou sooooo much

Answer 9

You're welcome. It seems you forgot to change the sign when you distributed -0.001 earlier.

Answer 10

woops