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justjm:

I need help on part C and D, how do I go about in solving?

justjm:

justjm:

@myeyeshurt

myeyeshurt:

Write a closed form expression for the area for -5 to c. It should be the sum of a few definite integrals

myeyeshurt:

From there divide by the interval c-(-5) to get the average value. You can set this equal to 1/2 as the problem requests

myeyeshurt:

Let me know if you need more detail

justjm:

So like this? \( \frac{1}{c+5}\left(\left(\int_{-5}^{-3}f\left(x\right)dx\right)+\left(\int_{-3}^{-2}f\left(x\right)dx\right)+\left(\int_{-2}^{0}f\left(x\right)dx\right)+\left(\int_{0}^{c}f\left(x\right)dx\right)\right)=\frac{1}{2} \)

justjm:

And then I evaluate the first few using geometry? \(\frac{1}{c+5}\left(\pi+1+2+\int_{0}^{c}f\left(x\right)dx\right)=\frac{1}{2}\)

justjm:

How do I solve for C now?

myeyeshurt:

Use FTC corrollary

myeyeshurt:

The integrand is F(c)-F(0)

myeyeshurt:

When evaluated

myeyeshurt:

But you can also just use 1/2 b*h since it's a triangle

myeyeshurt:

Here b=(c-0)=c and h is the y intercept

justjm:

Ohh I see, let me give that a try

justjm:

I tried using FTC but I was confused bc I didn't know what F(x) was

justjm:

So the area of that is just c because length is c and width is 2

justjm:

\(\frac{1}{c+5}\left(\pi+3+c\right)=\frac{1}{2}\) I got it now, thanks man. Do you have a suggestion for part D as well? Thank you very much once again

justjm:

Hold on, unless I did something wrong in the last step, I got a negative value for c.

justjm:

Nevermind, silly me, the area for the bottom bit is negative of course. Realized my mistake. So back to D, how do I do that?

myeyeshurt:

So h(6)=f(3) and you want h'(6) or f'(3)

myeyeshurt:

Since c is greater than 3

myeyeshurt:

It's just the slope of f

justjm:

Oh okay I got it, thanks. I find the slope with (c,0) and (0,2).

justjm:

I appreciate it brother thank you. God bless

myeyeshurt:

Yup!

myeyeshurt:

Wait you have to multiply by one half

myeyeshurt:

Cause of the chain rule

justjm:

Oh from the x/2? why would that matter?

myeyeshurt:

d/dx f(x/2)=1/2 f'(x/2)

justjm:

Oh okay I see. Thank you once again.

justjm:

One more thing, for part b is the answer -3 and 0, because the inflection point is the change in signs for g'(x) or f(t)?

myeyeshurt:

Idr any second derivative stuff tbh :(

justjm:

it's okay bro :) thank you

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