Math May 2012 question help!!

Test Preparation SAT Preparation
1

<p>file:///Users/polina1022/Desktop/photo.JPG</p>

<p>In the figure above, BE and AD intersect at point C. if AB=2 and CA=3 and BE=3 radical 5 what is the perimeter of triangle CDE?</p>

<p>file:///Users/polina1022/Desktop/photo-1.JPG</p>

<p>In the XY plane above, the graph of the function f is shown. For which of the following value of x does f(x)=f(-3)</p>

<p>Thank you in advance for your help :(</p>

2

<p>Please upload the photo…</p>

3

<p>Using Pythagoras Theorem on triangle ABC, we have
BC = sqrt(CA^2 - AB^2) = sqrt(3^2 - 2^2) = sqrt(5).
So
EC = BE - BC = 3* sqrt(5) - sqrt(5) = 2* sqrt(5).
Noting triangle DEC is similar to triangle ABC, we get
CD/CA = DE/AB = EC/BC = 2,
and thus
CD = 2<em>CA = 6,
DE = 2</em>AB = 4.
Therefore,
the perimeter of triangle CDE = 6 + 4 + 2* sqrt(5) = 10 + 2* sqrt(5).
Answer is (E).</p>