<ol>
<li>a. $2500
b. dollars, cost of extending cord to 30 meters
c. 120k- integration of 6rootk from (0,K)
d. 400 meters, thus 16000 dollars</li>
</ol>
<p>For questions 1-3 I’ve only missed 2 parts. :)</p>
<p>Good enough for me. haha</p>
<p>Now for 4-6.</p>
<p>How many points will I get if for 1(a) i put miles/min and not miles/min2, (b) wrong…I forgot to count the negative as positive!.</p>
<ol>
<li>(b)and I think (d)</li>
</ol>
<p>3.(a)
(c) made some mistake
(d) I got all the way up to x-400 and found the maximum with the f’(x) test. I know I didn’t get the answer, but how many points?</p>
<p>Then for the rest of those I got right.</p>
<ol>
<li>got 4. (b) wrong for sure.</li>
</ol>
<p>Someone check my #5 and #6 please.</p>
<p>I got 2/pi like bookworm,too. i forgot how. (man, i hope i get a 5 even if i screw up on some of the fr problems.)</p>
<p>Correct Answers:
- a. -.1 m/min2
b. 1.8 miles
c. t=2
d. Caren=1.4 miles<Larry=1.6 miles</p>
<p>Does anyone have a scale to check? I want to see what my FRQ score will be and how much I need on the Multiple Choice to get a 5.</p>
<ol>
<li>a. 4/3
b. no idea, sorry
c. integration of (square root of y- y/2)^2, from (0,4)</li>
</ol>
<p>Alright so I think for 4 I only got (b) wrong…and for that one I think I maybe set up the limits and stuff right so ya!!!</p>
<ol>
<li>a. -3
b. 8
c. 18
d. just write it out</li>
</ol>
<ol>
<li>a. -2
b. too lazy to figure out
c. 3ln(5/3)</li>
</ol>
<p>I got same as dstfan for the rest of 4. </p>
<p>I really can’t remember most of my answers. I got the same as dstfan for 1, only I got that Larry lived 1.809 from school (I laughed because 1+8=9 - dumb, I know :)). Also completely agree on 3 him/her.</p>
<p>omg I got all 5 right and dstfan you got 6a. wrong.</p>
<p>Alright just an example. Like you have the graph of f(x), to find the maximums, which is the next derivative down, you know they are the curves that are high up there. Use that same thing for this. you have the graph of f’(x) so to find the concavity and points of inflection you look for the curves high up there, which is the next derivative down.</p>
<p>I am pretty sure that 6a is only -2 because the minima or maxima of the first derivative is the zero of the second derivative and thus is the point of inflection.
Zero doesnt work because it has multiple tangent line.</p>
<p>Now can someone figure out my final score closely? I know scales aren’t out but a guesstimate? </p>
<ol>
<li><p>(a) i put miles/min and not miles/min2 (How many points off, or how much I get for that?)
(b) Half right. i got the meaning of integral. I got the first portion right.
(c) I put (2,4) and gave the reason that she headed back home from 2 minutes to 4 minutes because that at 2 minutes she changed her direction of travel since it is below the x axis or something. Can i get partial credit for that?
(d) Right.</p></li>
<li><p>(a) Right.
(b) Wrong.
(c) Right.
(d)Wrong.</p></li>
</ol>
<p>3.(a) Wrong.
(b) Right.
(c) made a small mistake.
(d) I got all the way up to x-400 and found the maximum with the f’(x) test. I know I didn’t get the answer, but how many points?</p>
<ol>
<li><p>(a) Right.
(b) Maybe got the limits.
(c) Right.</p></li>
<li><p>(a) Right.
(b) Right.
(c) Right.
(d) I got the tangent.</p></li>
<li><p>(a) Right.
(b) Right.
(c) Right.</p></li>
</ol>
<p>dstfan, you are correct that the min max of the first derivative is the zero of the second derivative, but you have to remember this. This is the graph of f’(x), so its zeros are the maximums of f(x). The maximums of f’(x) will be the zeros of f’'(x), which are possible POI, and since x=0 is the only one that can only be the answer I believe and think.</p>
<p>If you picked x=-2 that is a possible Maximum or Minimum Not a possiblE P.O.I…</p>
<p>What do you mean by multiple tangents? If you draw a tangent line below the curve from - to 0, you get a positive slope and from 0 to 3ln(x) you get a negative slope.</p>
<p>for 4b, anyone else get 8/3?</p>
<p>I remember getting 8/3</p>
<p>dstfan.
yes -2 is a POI but your flaw is that POI’s happen at both f’'(x)= 0 or UNDEFINED so like you hinted at their really is no tangent to the graph at 0, so its undefined.
the answer was at x=-2 and 0</p>
<p>indianjatt.
you are also partially correct. there is a possible max or min at -2 but theres also a POI there as well because the
slope of the circle changes from - to +</p>
<p>The minimas and maximas of the graph of f(x) are the zeroes of the derivative.
The same goes for the derivative, its minimas and maximas are the zeroes of the second derivative.
The point of inflection is when the second derivative is equal to zero, this means drawing a tangent line at x=-2 you get a slope of zero and thus this is a point of inflection.</p>
<p>well, points of inflections are critical points for the second derivative. According to the definition of critical points, you have to set the function to zero or undefined.</p>