Official ACT Math Thread April 2013

<p>Discuss/ask questions here.</p>

<p>Thought it was harder than usual. Some weird things ive never seen on practice tests before.</p>

<p>What was the answer to the stem-leaf plot graph?
What was answer to #19 the circle with three sectors? it asked for xyc maybe? I Put30</p>

<p>it was harder than normal for me, dont post questions/answers yet since not everyone has taken the test</p>

<p>I thought it was harder than usual as well. Seemed to be more trigonometry and geometry than usual although that may just be me.</p>

<p>well as long as everyone thought it was hard then im happy lol cause then theres gonna be a good curve, it was extremely easy though the first 40 questions or so</p>

<p>hawaii is in taking it now so you can discuss…</p>

<p>ok then i guess we can now :slight_smile: , for the stem and leaf plot question i believe 51/52</p>

<p>For the stem/leaf plot, I’m almost positive it was 52 because I remember finding it funny that the answer to question 52 was 52. But I could definitely have miscalculated so take that with a grain of salt</p>

<p>Also for the circle with 3 sectors one, I put 30 degrees as well. I don’t remember it too well but I did put 30.</p>

<p>Stem and leaf was 52 because it was between 51 and 53.
Question 19 was 30 degrees because it was 150 - (100 + 80) to find the overlap. Forgot the actual numbers on this one. </p>

<p>Anyone get 58? 58 was the question where xy was moved 120 degrees about the origin. I struggled with that one. I chose square root of 3, but I’m honestly not sure how I even came to that conclusion. Haven’t seen a question like this one on any of my practice ACTs before. If I get this one right, I’m hoping for a 36!</p>

<p>how about for the one where it said a= 3x and it was an angle measure or something? it said like x is between what and what, i think i guessed x is between 30 and 45</p>

<p>I also thought that it was harder than usual… There were some problems that I’d never seen on any of the practice tests that I’ve taken. Did anyone get the last question? I believe it was one asking about f^-1(x). I didn’t even understand what it was asking… then again it’s probably just…</p>

<p>Move the 120… Is 1 because 30 60 90 degree triangle and longer hypoth. = 2</p>

<p>That f-1 one was y=x^3-2</p>

<p>Pk12ab: the answer to the 120 degrees problem was 1 because the length of the line rotated would remain the same, 2 and if you translate that line down so that it touched the x axis, you would form a right triangle with an acute angle measure of 60 between the hypotenuse and short leg on the x axis. Therefore, you had a 30-60-90. The answer was 1.</p>

<p>was 1 b ?</p>

<p>@actsat
It was a right triangle with two acute angles. Lets call <A the one we are looking for. <B was the right angle, and <C was the other acute angle. 180-90 = 90. The other two angles had to add up to 90. Since the angle was 3a the angle was equal to (90 - <C) / 3 = a. Because <C has to be at least one degree, we can determine that a<30. Therefore the answer was between 15 and 30 degrees.</p>

<p>@Libera
You had to take the inverse of the function. This is done by placing y where x is and setting it equal to x. Then just solve for x. I think the equation was cube root of x + 2. By using the method I just explained, cube both sides and you get x^3 = y + 2. So the answer is y = x^3 + 2.</p>

<p>Please correct me if I made any mistakes anyone.</p>

<p>That ab one was def 2/root2
0<a<30</p>

<p>Quick Question</p>

<p>what was the answer to the one that said x=4 x^2 -ax +1 =0?</p>

<p>Also the one with rotating the segment counterclockwise I put root3 can someone clarify?</p>

<p>I don’t remember too correctly, but was there an option on the obtuse/right triangle one that sad 0-30? Or was it 15-30?</p>

<p>Thanks guys! That makes so much more sense now. I can’t believe I forgot how to do that on the test… curse all the times I fell asleep in math class…</p>

<p>@Like a sir
Thanks. Really mad at myself right now because it was so obvious. Spent around 10 minutes on the question just staring at it. Hopefully the curve will save my 36 and I didnt make any silly mistakes.</p>