<p>Exception, which ones do you need?</p>
<p>Here’s what I did for each of them on the FRQ for AB form A. Lemme know how you think i did:</p>
<p>1A. Integral of f(x) from 0-6</p>
<p>1B. Not sure if I did it right, but i found deriv of f(x) and substituted in 8 and then subtracted 108.</p>
<p>1C. 0 for t< 6
125(t-6) for 6<=t<7
108(t-7) + 125 for 7<=t<=9</p>
<p>1D. Integral of f(x) from 0 to nine minus 125+108+108</p>
<p>2A. (21-13)/(7-5)</p>
<p>2B. I didn’t do the trap rule formula, but I found all the areas of the trapazoids and added them together, so I put:</p>
<p>((0+4)/2)<em>2 + ((4+13)/2)</em>3 + ((13+21)/2)<em>2 + ((21+23)/2)</em>1</p>
<p>Giving me 85.5</p>
<p>For what it meant, I put it meant that’s the number of total ballots counted at 8 PM, in hundreds of entries.</p>
<p>2C. integral of E(t) from 0 to 8 minus integral of P(t) from 8 to 12, giving me 69.5 hundreds of entries</p>
<p>2D. Found deriv of P(t), which is 3t^2 -60t + 298 and set it equal to zero. This is where I ran into trouble b/c i have never remembered the quadratic equation 100% and I had a brain fart with some indecisiveness. So, unable to find what t is equal to, I tested t=8, t=9, t=10, t=11, and t=12, and found that t was the highest at t=8 and t=12 at 10 hundred entries per hour. </p>
<p>3A. Did a trap rule here:</p>
<p>((1000+1200)/2)<em>2 + ((1200+800)/2)</em>1 to give me 3200 people</p>
<p>3B. Increasing because the ride only rides 800 people per hour and the integral from 2 to 3 of r(t) is 1000.</p>
<p>3C. Time t=3. Don’t wanna show all the work again tho. Justification is that the value for the integral is highest at that point.</p>
<p>3D. Integral from 0 to 8 of r(t)dt minus 800t = 0</p>
<p>4A. Integral from 0 to 9 of 6-2x^1/2</p>
<p>4B. Pi times integral from 0 to 9 of (7-2x^1/2)^2 - 1</p>
<p>4C. Integral from 0 to 6 of ((y^2)/4)*3((y^2)/4)</p>
<p>5A. for g(3): 5+PI+3/2
for g(-2): 5-PI</p>
<p>5B. -2, 0, 2, 3 because the slope is either 0 or undefined at those points</p>
<p>5C. Was a tough one. Found deriv of h(x), which is g’(x) - x. Said x=3 cuz thats the only one that made sense. Dont remember what I put for other part.</p>
<ol>
<li>I have no idea how to do this. I suck at differential equations. My teacher always told me to separate the variables “like bad children”, so I did that for part A, along with something that might have been right, and then something that could have possibly gotten me a point or 2 for parts b and c, although I doubt it.</li>
</ol>
<p>Would they deduct points if I used integrals with variables in their limits in 1(c)? Also for 6 c, I forgot to integrate -1/2, would they be lenient on that grading?</p>
<p>If I got 2 out of the 3 inflection points on AB form A #5b and explained both correctly, would I get any credit? Or would it just be a point for points and a point for explaining…?</p>
<p>and for 2A of AB form A, I know you all’s answer is MVT, but it doesn’t make sense…it comes to 8/2=4, which is less than were in the box at t=5. I believe I put the same formula on my answer sheet, then put an arbitrary guess of around 18…? What would they do for the score of mine?</p>
<p>yeah violin, I did the same thing for 1(c)</p>
<p>Grr…I hope no points are deducted because then I think I got the whole free response sction right!</p>
<p>Beta, the 4 is the RATE in which they are being counted, when E(t) is the TOTAL number of ballots.</p>
<p>RC, i did that for 2c too. </p>
<p>And did anyone get this for 5c: 1-(e^x)/e</p>
<p>I don’t think its correct. I didn’t properly integrate with C : (. How many points would be taken of if my method was good except for one step?</p>
<p>For 2b the meaning is the mean number of ballots in the box at any given time from t=0 to t=8.</p>
<p>And i got .75 for 5a.</p>
<p>LOL, that makes me feel a bit better Esplin. Anyways, can’t tell ya for 5C, no clue on that one. If you didn’t get the correct answer and you screwed up in the integration, I don’t think they will award any points for that particular step.</p>
<p>Actually piccolo, since the integral is from 0 to 8 it is at time t=8.</p>
<p>dang, I didn’t see rate :(. What if I have the MVT set up correctly in the box…is there a chance they’ll give me credit if I have a random 18 there? lol</p>
<p>rc, but what wasn’t it an average value? I thought since there was a 1/8 before the intergral… I might be totally wrong though</p>
<p>Beta, I think if you have MVT they may give you 1 point since you know that that’s why the rate is 4.</p>
<p>Piccolo, that would be the case if it were an indefinite integral I believe. The 1/8 is there because you are using a trapezoidal rule.</p>
<p>Ok thanks. What about the ones that have multiple points, and I only answered one or two? Like in #5 c I got x=3 with an explanation? I think I’ll get more partial credit than I had originally thought after taking it! :)</p>
<p>Is the BC score determined from the whole test or just the BC parts?</p>
<p>Indeed, my 2(d) answer (post #28) was incorrect. While t = 9.184 is where P(t) has a relative max (P’(t) changes from + to -), P(t) has an absolute max at t = 12, since P(12) = 8 > P(9.184) = 5.089.</p>
<p>can someone tell me why the answer is 1.25 for 5a?</p>
<p>And when will they come out with the scoring guidelines?</p>