district2 2010

[smeag]

please help on: 16, 30, 33, 34, 45, 47, 49, and 58
thanks!

[nsguy1350]

16. Remove the A,3,5,7,9 to get a deck full of:
2,4,6,8,10,J,Q,K. 32 cards total.
The probability that the first is a face card is [unparseable or potentially dangerous latex formula], and the probability that the second is a factor of eight is [unparseable or potentially dangerous latex formula]. Multiply those to get [unparseable or potentially dangerous latex formula], or D.

30. [unparseable or potentially dangerous latex formula], so k = 15, for B.

33.This is the power series for [unparseable or potentially dangerous latex formula]. You plug in 5, so [unparseable or potentially dangerous latex formula] is about -0.9589, which is C.

34. Put it in standard form (actually, a bit off standard form, but I do it that way), which is [unparseable or potentially dangerous latex formula], then your directrix will be k + p since this is a negative quadratic that opens down (no, that is not redundant, the rules for parabolas that are negative and are pointing left or in a another direction are different). If it opens down, k + p, up, then k-p.

45.[unparseable or potentially dangerous latex formula]
[unparseable or potentially dangerous latex formula]. Solve for c, to get $7360, or C.

47. This one was weird, I skipped and nobody here knows how to do it. It just sounds like it's a completely bad problem to me, unsolvable, but it might be and I can't help you here if it is solvable.

49. I put one force on the positive x axis, making the forces vectors. Then, one vector is at 0 degrees, and another is at 46.
[unparseable or potentially dangerous latex formula]. Take [unparseable or potentially dangerous latex formula] to get magnitude, which is D.369.

58. I did [unparseable or potentially dangerous latex formula], which gave me 12.75, or C. I didn't have to divide by 100, I just did because I neglected percents in the numerator.

Hope this helps! I'm off to TMSCA State tomorrow!

Also, today, I took 2 Math tests, '09 Region and State. I have a lot of work to do if I want to get to State this year... 248 on Region (43 right, 5 wrong, 12 skipped), 252 (45 right, 9 wrong, 6 skipped) on State.

[smeag]

some more: 34, 50, 51, 52, 54, and please clarify 58

[nsguy1350]

34. Look up directrix #. That should be better than whatever I say.

50. Polar graph. Anytime you see [unparseable or potentially dangerous latex formula], that's automatically a spiral.

51. Another polar question. This is a lemniscate graph. Once you see what it looks like, you'll see that it is symmetric by the line [unparseable or potentially dangerous latex formula].

52. Take the harmonic mean of the sides to get the length of the segment that goes through that intersection.

54. Looking at the ruler, you can see that A is at [unparseable or potentially dangerous latex formula]. Divide that by 4 to get [unparseable or potentially dangerous latex formula].

58. The mathematical expectation is the event you would expect to see on average, not necessarily a possible event. The mathematical expectation of a fair coin, treating heads and 0 and tails as 1, is .5. For a die, it's 3.5, beacuse [unparseable or potentially dangerous latex formula].
For this, you can expect 5 people 15% of the time, 10 30% of the time, 15 40% of the time, and 20 15% of the time. If we multiply the chance of each, then divide by 100%, we get the mathematical expectation. [unparseable or potentially dangerous latex formula].