<p>@mattgtodude, for #4) f(x)= -2 at x=5/2, not 3/2 rite?</p>
<p>These are the answers I remember i got…
1a) increasing speed, both v(t) and a(t) are going in same direction</p>
<p>2a) -8/3 degrees per minute
2b) avg. temp of tea from 0 to 10 secs, 52.95 degrees celcius avg temp
2c) -23 degrees. Delta T from 0 to 10 sec.
2d) B(10)=34.18 degrees celcius, and an answer of 8.81 degrees cooler</p>
<p>5a) 1411 tons
5b) W’’ = 1/625 (W-300), didn’t get to finish it
5c) it was a separation of variables but i didn’t get to finish it either</p>
<ol>
<li> .
a. 1-2sin(0) = 1
e^(-4*0) = 1
Since they are equal, f is continuous
b. F’(x) = -2cosx for x< 0
F’(x) = -4e^(-4x) for x>0
To find where f’(x) is at -3, use -4e^(-4x) since you know that –2cosx cannot be below -2.
-4(e^-4x) = -3
e^(-4x) = .75
x = ln(.75) / -4
c. .5 (integral from -1 to 0 of the first function + integral from 0 to 1 of the second function)
.5 (x+2cosx from -1 to 0 + -.25e^(-4x) from 0 to 1)
.5 ( -1 + 2cos-1 – 0 – 2cos0) + .5(-.25 – (-.25(e^-4)))
.5(-1 + 2cos-1 – 2) + .5 (-.25 – 1/(4e^4))
-1.0869</li>
</ol>
<p>for the multiple choice question with the left reimann sum with 4 rectangles, what did you put?
(you had to find the area above those rectangles)</p>
<p>i got the integral from 0 to 4 f(x) - the sigma thingy with a 4 above it and n=1 below it</p>
<p>for 4c since the 2nd derivative of g is undefined at x=0 (cusp) but x=0 is still in the domain of g, doesn’t a point of inflection occur there since the 2nd derivative of g (first of f) changes sign?</p>
<p>@BadGirlsClub - when I took the test I was pretty confident with that answer but starting to second guess it now. @Wynter you are right, i forgot about that.</p>
<p>for 6a, i think just saying they end at the same point is not enough. I feel like you had to put that as lim x->0 f(x) = 1, indicating it is continuous</p>
<p>i think as long as you show that the one sided limits are equivalent, then your good. but who knows. does anyone know when they put the answers up?</p>
<p>Omg guys this is so reassuring!! I actually got more than I thought right since everyone’s getting similar answers!! ^^
AWESOME. 5, here I come
Best wishes to everyone too</p>
<p>@BadGirlsClub yes that is true for the AP test without a curve. remember again there will be a curve so it could be less than 68 for a 5. i HIGHLY doubt it would ever be more than they originally set it as</p>
<p>I think I definitely got at least 30 on the free response now, probably more but i can’t remember some answers now. I hope that’s enough to get me over the border if I failed on my MC for some reason (took at least 7 completely random guesses)</p>
<p>However we don’t know which part will be worth more for its smaller parts (like seperable differentiation has a lot of different points that go into it) plus you can get some credit for attempting something in the right direction or simply recognizing something that starts the problem.</p>
<p>I’m guessing you guys may have done a lot better than you think and random points will help</p>
<p>@naokifresh thanks my teacher wasnt sure and neither was the head of the math department at my school. do you know how much the curve usually is?</p>
<p>An update on 5b
DW/DT = 1/25W – 12
D2W/DT2 = 1/25(DW/DT)
D2W/DT2 = 1/25(1/25W-12) = 1/625W – 12/25
Since W is bigger then 1400, 2nd derivative will be positive. Since W is Cup, it will be an underestimate</p>
