*The Official June 2012 Sat II Math Level 2 Thread*

<p>for the one that asked for the perimeter of an equilateral triangle with verticies (0,3) and (4,0) the answer was 15 i think</p>

<p>kobebryantthejr, thats actually 41.</p>

<p>Anyone on the F(x+1)/2</p>

<p>F(2) = 4
F(3) - F(1) = ?</p>

<p>I got 6, but I want to hear your responses just to make sure :)</p>

<p>Crap, yeah.</p>

<p>Does anyone remember what number 38 was? Also, why was the revolving x cone one 6pi and not 4pi?</p>

<p>In the rotating figure, I didn’t get an answer that matched exactly, but it was somewhat closest to 18, so I marked it (it was C D or if I remember correctly).
Still, I believe that calculus wasn’t necessry to solve it.</p>

<p>What was the answer to the question with the 60mph ---->
and 40mph <------</p>

<p>My reasoning was volume of a cone = 1/3pi * r squared * h
r was 2
h was 3</p>

<p>1/3 * 3 = 1 so its just 4pi?</p>

<p>Aperture - I put average = 50mph.
I just used what I learned in physics :o</p>

<p>oh thank goodness.
I thought it was way too simple</p>

<p>A bit less than 50 miles because you’re driving for less time with the 60 miles per hour, so the average is actually 48.</p>

<p>Edit: @aperture, it wasn’t that simple :(</p>

<p>@Corrax
it rotated around the X
R should be 3</p>

<p>less than 50 bc more time was taken going at 40</p>

<p>It was less than 50, actually 48
And the cone one was 6pi</p>

<p>well. that’s a -4 for me … 1 omit </p>

<p>im crossing my fingers</p>

<p>@Corrax</p>

<p>I think I remember the question asking for the volume if the line was rotated around the x axis. This would switch the r and h values if you rotated it around the y axis instead.</p>

<p>Oh. Forgot about the different time part (I put same time leaving and coming back).
That’s -1.</p>

<p>@aperture if you use 3 for r then you get 9pi, I know the correct answer is 6pi but how?</p>

<p>Edit: oh thanks narwhowl</p>

<p>The one about being divisible by 2, 3 and 4 i put I,II,and III because i thought it said for all integers n>1
Am i right or not??</p>

<p>i’m pretty sure it was just divisible by 2 and 3 cause >0? not 100% though</p>