Official ACT Math Thread April 2013

<p>Does and one remember what the answer choice for the stem and leaf one was?</p>

<p>@yoskis </p>

<p>That was the median one, correct? I believe it was 52 because I got 51 and 53 and had to average them.</p>

<p>Pretty sure it was 52</p>

<p>The one with the coterminal angles - what does coterminal mean? Never once have I seen that word through all of trig and calc. </p>

<p>Ok the one towards the end where a line segment from (2,0) to (4,0) was reflected 120 degrees, I got the answer to be one. My thinking was that by reflecting it 120, the angle created in the new “decreasing” line segment would be 60. So then, the “x” component (which was basically what we were trying to find) would be the length of the segment * cos60, which would give you one. Anyone get that too?</p>

<p>Coterminal just means that they are the Same angle. For example, 30 is the same as 390. For that problem you had to set pi equal to 180 and then keep subtracting 360. The answer ended up being 60.</p>

<p>Does anyone remember the answer choices for the number of people that own fish when 35 more people were surveyed? I cannot remember which choice I chose. I know one was 205/225.</p>

<p>Was there a 215/225?</p>

<p>I remembered the conversion between radians and degrees, but I forgot what coterminal was. I think I was thinking supplementary angles, so I got the 60 and then subtracted it from 180 :(.</p>

<p>In my previous post (with the question), I meant to say 25, not 35.</p>

<p>does anyone remember the correct letter choice for #58 with the line rotation or whatever? People are saying the answer is 1 but I only remember putting B/G</p>

<p>Does anyone remember the question regarding the foiling of 6,π,i, and I believe 7?</p>

<p>Mimi I am pretty sure it was 1. The rotated segment was 2 long, and by being rotated 120 the triangle formed ended up being a 30-60-90. The hypotenuse was 2, and we were trying to find the shortest side so it had to be half of the hypotenuse.</p>

<p>OH I misinterpreted your question, sorry. I think it was either the 2nd or 3rd letter, it’s hard to remember for sure…</p>

<p>What I did was plugged in angle values based on how it looked, so I gave 120 to the obtuse, and then I think I gave like 40 or 30 to the 3a angle. I think the mistake you made that they kind of expected a lot people would make is bubble in the logical answer that the degree of the 3a angle is between like 30 and 45. That is most likely true; however, you need to divide that by three because it asked for what a equaled, so it was 0-15 (I think that was the scale of the choice).</p>

<p>Nope. If something is directly proportional, it is division not multiplication. Think about it, radians are directly proportional to degrees, so pi/180=xpi/xdegrees. It’s like in the gas laws, P1V1=P2V2, because they’re inversely related. As pressure increases, assuming fixed other conditions, volume has to decrease. Sorry :/</p>

<p>Was the percentage of people with just one animal 70%?</p>

<p>Also. One more question was about the d and t graph. It was just a horizontal line. It could not have been circle, +/- slopes right??</p>

<p>Yes curry, the percentage of people with one pet was 70% since the percents given were additive. Personally, I put a horizontal line like you for that other question, but others are saying that the question was asking for total distance vs time which would make the answer a + slope. I personally thought it was asking for speed vs time or something like that</p>

<p>it was positive slope since it was asking time vs distance , and so distance has to increase with time so positive slope</p>

<p>No. She moved at a constant rate. Therefore, the slope must me horizontal</p>

<p>she moved at a constant rate but her distance was increasing. If you are running at 10 mph, you are increasing your distance. After 1 hour your 10 miles away, at 2 hours your 20 miles away, etc… Just because she is moving at the same speed doesnt mean that shes not moving anywhere lol</p>