May 2010 - Math Level 2

<p>i think it was 78.8 or 79 or omsthing</p>

<p>the 5,6,7 was a law of cosines problem
49 = 25 + 36 - 2(5)(6)Cos C
-12 = -60CosC
Cos^-1(-12/-60) = was like 110 or something to lazy to go downstairs and get my calculator</p>

<p>102 i think</p>

<p>i just did Cos^-1(-12/-60) on my calc and i got 78.4. howd you guys get 102? :/</p>

<p>if it was 110, then cos 110 would be negative and it won’t equal to 12/60 or -12/-60</p>

<p>Do we have a confirmed answer for the last question? I answered it but probably missed it. Overall, I strategically skipped two and could have got the rest, so I’m in decent shape for 800.</p>

<p>I got 78.something as well.</p>

<p>i got 78 degrees </p>

<p>cos^-1 (1/5) = 78.463…</p>

<p>i just redid the last question (#50) and got 0.92387 anyone else got that too?</p>

<p>What was the last question?</p>

<p>f(x/2) = square root of 1+f(x) / 2
and f(a)= 0
what’s f(a/4)?</p>

<p>i got 0.92… too</p>

<p>I put whatever my calc said for cos^-1(-12/-60) so if it was 78 or whatever then that’s the right answer</p>

<p>i put II and III</p>

<p>I said 78. xD</p>

<p>So was it 78 or 102?</p>

<p>was that law of cosines question towards the end? like #46 or #40 or something?</p>

<p>i confirm 78.4 by the way…
the cosine was positive because you have to divide c^2-a^2-b^2 which is negative, by negative 2ab, which gives a positive answer.</p>

<p>LOL I just picked up my calculator and it still has cos^-1(12/60) entered in it from when I took the test, and it does indeed say 78.463</p>

<p>i just redid the last question (#50) and got 0.92387 anyone else got that too? </p>

<p>^ What was the question again?</p>

<p>Edit: Nevermind I think I remember…I redid it and got that as well.</p>

<p>what number was the law of cosines one?</p>