Question

Suppose that f is given for x in the interval [0,12] by
x= 0 2 4 6 8 10 12
f(x)= 11 14 17 18 17 14 12
A. Estimate f′(2) using the values of f in the table.
f′(2)≈
1.5(This is right)

B. For what values of x does f′(x) appear to be positive?


(Give your answer as an interval or a list of intervals, e.g., (-infinity,8] or (1,5),(7,10) .)

C. For what values of x does f′(x) appear to be negative?


(Give your answer as an interval or a list of intervals, e.g., (-infinity,8] or (1,5),(7,10) .)

Answer 1

@ganeshie8

Answer 2

how long have you been standing there? D:

Answer 3

long time @PeterPan

Answer 4

I dont know how to do part B and C

Answer 5

Well, d'uh... :D

Just kidding~

Well, that's why I'm here, right?

B and C have the same feel to them, they may as well have been the same question...

Ready to finally deal with them?

Answer 6

yeah :D

Answer 7

Okay, the derivative would APPEAR to be positive between an interval if there was an INCREASE in the value of f(x)...
for instance, between 0 and 2, the value of f(x) increased by 3, from 11 to 14.

So..... the derivative appears to be positive in the interval (0,2)

Care to find the others?

Answer 8

(0,2),(2,4)(4,6)= positive

Answer 9

or simply (0,6), I bet
I don't know how your teacher prefers it, you would know better :>

Okay... so if the derivative appears POSITIVE where the value of f(x) went UP, care to take a guess where the derivative appears negative? ^.^

Answer 10

(0,6) and (6,12) was correct:D thanks man

Answer 11

no problem :D