Help with some math questions!!

Test Preparation
1

<p>I keep getting this problem wrong, and i can't figure out why.</p>

<pre><code> [ x ] . [ -1 ] . [ 0 ] .. [ 1 ]
</code></pre>

<p>----- l ------ l ----- l
[ f(x)] [ 1/8 ][ 1/2 ][ 2 ]</p>

<hr>

<ol>
<li>The table above shows some values for the function F. If F(x) = ka^x for some constants k and a, what is the value of a?</li>
</ol>

2

<p>k is obviously 1/2</p>

<p>1/2 a^x = f
.5a=2</p>

<p>a=4</p>

3

<p>^To clarify what he did, plug in x=0 to find f(0)=k=1/2.</p>

<p>Then plug in x=1 to find f(1)=1/2a^1=2 and solve.</p>

4

<p>Thank you very much.</p>

5

<p>Other questions I am having difficulty with.</p>

<p>1.
A pyramid shown has an altitude (h) and a square base of side (m). The four edges that meet at (V), the vertex of the pyramid, each have length (e). If (e)=(m), what is the value of (h) in terms of (m)? </p>

<p>(A) m / square root2</p>

<p>(B) m square root2 / 2</p>

<p>(C) m</p>

<p>(D) 2m / square root3</p>

<p>(E) m square 2</p>

<hr>

6

<p>Could someone help solve this problem?</p>

<p>In an election, 2.8 million votes were cast and each vote was for either Candidate 1 or Candidate 2. Candidate 1 received 28,000 more votes than Candidate 2. What percent of the 2.8 million votes were cast for Candidate 1?</p>

<p>(A) 50.05%
(B) 50.1%
(C) 50.5%
(D) 51%
(E) 55%</p>

7

<p>@Corash</p>

<p>28,000 / 2.8 mill = 1%.</p>

<p>Votes for candidate 1 + votes for candidate 2 = 100%</p>

<p>Votes for candidate 1 = votes for candidate 2 + 1%</p>

<p>Substituting in…</p>

<p>2 * Votes for candidate 1 - 1% = 100%
Votes for candidate 1 = 50.5% (C)</p>

8

<p>^ almost correct. 28,000 as a percentage of 28 million is .1%, not 1%, so the correct answer is 50.05%</p>

9

<p>To answer your pyramid question:</p>

<p>Draw a right triangle with these three points as vertices: the top vertex of the pyramid, one vertex of the base, and the center of the base. The hypotenuse of this triangle is the length of one of the four “edges,” which is e=m. One of the legs is simply the altitude, h. The last leg is half the length of the diagonal of the square base. The full length of the diagonal is m<em>rad2, so the length of this leg is m</em>rad2/2. Using the Pythagorean Theorem,
h^2+(m<em>rad2/2)^2=m^2
h^2+m^2/2=m^2
h^2=m^2/2
h=m/rad2, or m</em>rad2/2, which is choice B</p>

<p>EDIT: choice A is the same as choice B, so either one works.</p>

10

<p>thk you all very much</p>