Discussion of 2009 AP BC Calc Free-Responce Answers

<p>Number 3 a and b I got from:
[Free</a> Math Help.com - Homework Help! • View topic - 2009 AP Calculus BC Test Answers](<a href=“http://freemathhelp.com/forum/viewtopic.php?f=3&t=34183]Free”>http://freemathhelp.com/forum/viewtopic.php?f=3&t=34183)</p>

<p>Answers -> Please add to list
1.
a) -.1 m/s^2
b) 1.35
c) t=2
d) Caren
2.
a) 980
b) t=1.363
c)387.5 (its was 38X.5)
d)21.052
3.
a)12.722 m
b)1.936 seconds
c)1.5488m
d)
4.
a) 4.25
b)2+4(x+1)-6(x+1)^2
c)6-4e^(-1/3)(e^(-x^3/3) (if i remember correctly)
5.
a) -3
b) 8
c)18
d)
6.
a)(x-1)^2n/n!
b)(x-1)^2n/(n+1)!
c)-INFINITY to +INFINITY (aka convergent everywhere)
d) no points</p>

<p>1.
a) -.1 m/s^2
b) Distance traveled by Caren; 1.6 m
c) 2 minutes
d) Caren
2.
a) 980 people
b) 1.363 s
c ) 387.5 hours
d) .776 hours
3.
a) 12.06 m
b) 1.936 s
c) 12.94 m
d) 1.51 radians
4.
a) 4.25
b)2+4(x+1)-6(x+1)^2
c)6-4e^(-1/3)(e^(-x^3/3) (if i remember correctly)
5.
a) -3
b) 8
c) 18
d)
6.
a)(x-1)^2n/n!
b)(x-1)^2n/(n+1)!
c)-INFINITY to +INFINITY (aka convergent everywhere)
d) no points</p>

<p>Isn’t 4 c) 2+4(x+1)-12(x+1)^2 ? Cuz f’’ = -12</p>

<p>^ Ah nvm its divided by 2!</p>

<p>Posted this on the other thread.</p>

<p>1a) -.1 miles/min^2
1b) 1.8 miles, total distance travelled on time interval in miles
1c) t=2, velocity changes sign
1d) Caren 1.4 miles < Larry 1.6 miles</p>

<p>2a) 980 people
2b) t=1.363, second derivative test
2c) 387.5 hours (first fundamental theorem)
2d) .776 hours</p>

<p>3a) dy/dt = 0 @ t=.3673, so 12.061m
3b) A = 1.936 seconds
3c) s = 12.946m
3d) arctan(dy/dt/dx/dt) = 1.519 radians</p>

<p>4a) 4.25
4b) 2+4(x+1)-6(x+1)^2
4c) y = -4/e^(1/3) * e^(-x^3/3) + 6</p>

<p>5a) -3
5b) 8
5c) 18
5d) y+2 = 3(x-5) tangent line; y-3 = 5/3(x-8) secant line, just plugin and state since the graph is always concave down, tangent line over approximates, secant line underapproximates</p>

<p>6a) 1 + (x-2)^2 + (x-1)^4 / 2 + (x-1)^6 / 3! + … + (x-1)^(2n) / n!
6b) 1 + (x-1)^2 / 2 + (x-1)^4 / 3! + (x-1)^6 / 4! + … + (x-1)^(2n) / (n+1)!
6c) -inf < x < inf
6d) no points of inflection since original function is an always positive even function, so second derivative is an always positive even function, indicating concavity never changes. if you show the second derivative, you’ll see that it’s always >=1.</p>

<p>Estimated…what would be my raw score from this section if I got:</p>

<p>1a) right
1b) right
1c) right
1d) right</p>

<p>2a) right
2b) right
2c) right
2d) wrong…thought it was from [1,2]…may still get 1 point</p>

<p>3a) I think right
3b) Right
3c) I think right…either got this one or 3a right
3d) have the right formula…answer off by .06</p>

<p>4a) may have gotten 4.5…but almost correct if not completely correct
4b) can’t remember
4c) can’t remember</p>

<p>5a) think i got the reciprocal instead…ugh
5b) right
5c) right
5d) right…maybe -1 for a sucky explanation</p>

<p>6a) right
6b) close to right
6c) right set-up, used wrong answer from 6b though so got it wrong
6d) wrong</p>

<p>I’m thinking around…39?
Ouch. Does that suck? haha</p>

<p>^ If 39, you only need like 25 points from MC, which isn’t too hard</p>

<p>"^ If 39, you only need like 25 points from MC, which isn’t too hard "</p>

<p>^To get a 5, you mean?</p>

<p>I really only NEED a 3 to get credit at my school…but a 5 would be really nice.</p>

<p>^ Yes… lol. I bet you’re at ease now haha. With 39, you only need like 12 points from FRQ’s to get a 4. With 39, you already have a 3 I believe</p>

<p>39/54 is pretty damn solid if you ask me considering 63-66 total is need to get a 5.</p>

<p>don’t worry, i messed up my numbering on the entire calc multiple choice section (ie i ended on question 93 somehow, and did not have time to change it), but still can get a 5. the scaling is usually really generous. My math teacher, who has this down to a science (last year he got all 5s except one 4) and he said on an easy test, it would be 70 raw, and usually around 60 raw score (out of 99 points). I only need a 4 thank God b/c with my mistake, it looks more like a 4</p>

<p>does anyone else have any thoughts on my possible score. I think I got all but 6c, 3c, 2d, and maybe one or two points off. I also got partial on 6c, and I think i did really well on non calc multiple choice, if only i didn’t make that stupid mistake!</p>

<p>i think i could get about 40-46 on free response, so if you 65, i need a 19 on the non-calc (and hope with the mistake, i break even on the calc b/c my mistake is somewhere around 85 - i left 2 blank instead of one).</p>

<p>That be cool to get a 5! But do you think I can expect a 4 for sure?</p>

<p>And when do the scoring guidelines come out?</p>

<p>I always do better on the FRQ than M/C though…so that scares me a little.</p>

<p>^ Do you mean out of 108?</p>

<p>^ Do you mean out of 108? </p>

<p>yep</p>

<p>Sry it was directed at hawkswim, since he said it was out of 99, but its really out of 108</p>

<p>Oh haha. my bad.</p>

<p>someone up above said free responses were 54 so i added 28 and 17, but forgot that free responses are out of 63. do those scales still stand (the 60-70 raw score), also what is the usual raw score for a 4 (i need a four and think i got around 43 on free responses so i hope that i only need about 14 on the multiple choice (now i would have a 57) would that be a 4 or 3?</p>

<p>No its out of 108 cuz the MC score is multiplied by 1.2, so both parts are out of 54 for a total of 108. 50’s for your raw score would give you a 4, mid 60’s is a 5</p>

<p>so it is possible that if i get 75% of non-calc mc (would have 23 points here), and got 75% of the free response (41) and got none on the calc portion (i screwed up numbering so i think i will break even on this), then I may get a 5, but definitely a 4.</p>