Official October ACT Math Thread

<p>what was the answer to the concentric?? circle?
I guessed A</p>

<p>21.99 for the gas</p>

<p>64 for perimeter of the para</p>

<p>24 for the area of rhombus</p>

<p>the avg of the gas
then the 3% of 5th yr</p>

<p>plesae some answer this question</p>

<p>was the x |x| number is positive one like in the 40s like maybe 47 or something or was it in the 50s…</p>

<p>it was 5! so 120, order does not matter</p>

<p>never positive.</p>

<p>ya i know the answer was never positive but was it like # 40 or somewhere inthe 40s…</p>

<p>you guys get like 54?
18 + 3 = 21…difference is 15
18(3)= 54</p>

<p>it was 120, no doubt.</p>

<p>thanks for the explanation question. i finally understood. <em>facepalms</em> i was staring at that one for ages and couldn’t figure it out!</p>

<p>zeek, it was the sqrt of 27:</p>

<p>the hypotenuse is 6. to find the height, we need to divide the triangle in half. thus the base is 3, and the hyp is still 6. using the pyth. theorem, we get:</p>

<p>36= 9 = x^2</p>

<p>x = sqrt(27), which is app. 5. so the answer is 5.</p>

<p>I said 12 for the area. 1/2bh for rhombus isnt it?</p>

<p>Dman…</p>

<p>24.</p>

<p>1/2 X 6 X 8</p>

<p>what about
a^x < (-a)^x</p>

<p>even and something else…i forget</p>

<p>n is more then m and even</p>

<p>I thought the coordinate vertex one had to be both negative since it was a rotation and the original was in coordinate I on the graph.</p>

<p>m < n and n is even</p>

<p>overachiever, do you mean quadrant I? and it was (-3,2) because that would form a 90 degree angle. i hope this is the question you are talking about :P</p>

<p>the square thing was 1/16</p>

<p>Zens, you’re correct. It’s m<n and n must be even. this is because -a raised to an even power is a positive number. if it was odd, it would be negative and thus would not apply. so we cross out all of those.</p>

<p>now that we know that n must be even, that puts it on the same scale as a^m if m is equal to n. thus in order to make -a a bigger number than a, the n must be larger than m.</p>

<p>rhombus area was 24. and Check, is the answer the negative of the x coordinate and the y coordinate is the same? what were the original coordinates?</p>

<p>@tbonus, yes.</p>

<p>sno, for the 90 degree vector problem, the original coorinates were (2, 3). so the constructed coordinate had to be (-3, 2) because any x coordinate less than 3 for the given coordinate point would form a 45 degree angle with the horizontal. </p>

<p>so (-3,2) sounded right.</p>

<p>(0,7) for midpoint</p>

<p>the length of that side of the rectangle was 36 with x = 20</p>

<p>AC/AD for sin</p>

<p>whats the concentric circle one</p>