Okay, i'm doing a calculus question that has to do with someone driving a four hour drive regularly, and if s(t) represents her distance (in miles) from home t hours into the trip, the s(t) is given by s(t) = -5t^3+30t^2
We have already figured out parts A & B, how far from home she was after 1 hours, and how far apart the two cities are.
Part C is this:
How fast is she driving 1 hour into the trip? 1.5 hours into the trip?
The book gives me the solution, but I don't get it. It tells me to go through the four steps of finding a derivative, and that the answer is s'(t) = -15t^2 + 60t
My problem is, I don't know how they came up with that. I know in the steps I've done before my first step had to be to replace x with x+h (in the rule of f(x)).
What's x in this question? Is it the t? or the s? and then, I'm supposed to say to let f(x) = something
What's the f(x) = something??
Sorry if this question is long, I'm trying to include as much detail as possible.
2007-05-06
14:56:38
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3 answers
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asked by
dramaticanny
2
in
Mathematics