June 2010: Math II

<p>answers:</p>

<p>which could not be the range: (1,2,3)
contrapositive of the less than 3 so greater than or equal to 3
ln was .56 or something idk it worked on the calculator
i think the laser question is 1037 look at that persons explanation a while back
9.something degree angle</p>

<p>i think t > or = 3x whatever</p>

<p>I got 987 for the satellite one, it was tan(.05) = x/225, so x = 5280<em>225</em>tan(.05) - 50</p>

<p>sententia did you convert miles to feet?</p>

<p>wangh1, i think you forgot to subtract 50 ft, since it said the “edge” of the disk.</p>

<p>K i remember the 2/5 3/5 question now- you take the inverse tan of 3/5 minus the inverse tan of 2/5 and you get 9.2 which was a.</p>

<p>For the rotation one, you simply take the volume of a cone using r=3 and h=2 and get 18.9</p>

<p>laser question was not 1037 the question asked for the distance from the edge of the satellite, 1037 was the distance from the center of the satellite so you had to subtract the radius which was 50 to give you 987.</p>

<p>What was the question with abs(b) - abs(ab) over (a-1)?</p>

<p>@wangh </p>

<p>you’re wrong. either tan or law of sines would work to solve it. the reason some people got 1000 something is because they forgot to subtract 50 since it asked for distance from the edge. the answer was B, 900 something</p>

<p>I did arctan(50/(225*5280)) to get the actual angle. Then I added .05 degrees to this angle to get the error-shift. I’ll call the new angle “a”</p>

<p>Then I believe I set tan(a) equal to x/(225*5280), x being the “new” radius. Then subtracted 50. Got 1037, D.</p>

<p>Guys, the question that said
Domain= (1,2)</p>

<p>what is range?</p>

<p>… how did you do that?
i guessed it was 1,2,3…</p>

<p>and how many miles away from the disk did it give you for the initial value… i want to redo this problem and see what i get</p>

<p>2/5 3/5 was definitely 9.12 degrees. I studied how to do that for my Pre-Calc Final the other day. You use:</p>

<p>m1 + m2
________ = tanx
1 - m1m2</p>

<p>It might be subtraction in the numerator and addition in the denominator, but I remember I tried both and got the answer.</p>

<p>^I said 1, 2, 3 b/c there can’t be 3 ranges for 2 domains, you know?</p>

<p>As for the space problem. I setup a triangle with an altitude going from earth to the disc-end. The disc end = 50 + 50 (the 50’s are seperated by the altitude). Then you can do Pythag Theorem to find the ends of the disc. From there, it’s just 2sin.05 (2 because you need to do it twice for both halfs of the triangle) and got 1037.</p>

<p>yeah, you needed to do it twice because there were two sides where it could potentially miss</p>

<p>The laser question was definitely 987. I think the people who got 1037 forgot to subtact 50 (the radius of the disk) at the very end.</p>

<p><strong><em>Consolidated List of Answers</em></strong>
Laser-disc space problem = 1037 feet (EDIT: Or 987, I think I may have forgotten to subtract the 50 -_-)
Angle between 2 lines = 9.12 degrees
Domain 1,2 = Range 1,2,3 (can’t have 3 values w/ 2 in domain)</p>

<p>b greater than or equal to 3</p>

<p>yea that was my thinking too… but it was kinda… so obvious that i thought i was tricking myself? </p>

<p>also, i remember getting 155 for geometric series </p>

<p>and the graph of inverse was D or something.</p>

<p>also, average speed had to be less then 50?</p>

<p>just redid the laser-disc problem and i am certain it is 986… the horizontal distance from the center of the disc is given by tan (.05) multiplied by 1188050, which is the 50 ft radius plus the 225 miles. you then take this horizontal distance and subtract 50 to get the distance from the outside of the disc</p>

<p>i got 155 i think, and also less than 50, inverse was just flipped over y=x</p>

<p>ok to settle the laser debate ill prove it using law of sins</p>

<p>sin(89.95)/225 = sin(.05)/x</p>

<p>x = .19635 then convert that to feet from miles = 1037ft</p>

<p>then you have to subtract 50 because that is the distance from the center so the distance from the edge comes out to 987.</p>

<p>x = 987</p>