BB2 Math problem help

Test Preparation SAT Preparation
1

<p>pg 468 #16</p>

<p>A positive integer is said to be "tri-factorable" if it is the product of three consecutive integers. How many positive integers less than 1000 are tri factorable?
The answer is 9</p>

<p>pg 519 #19</p>

<p>A certain function f has the property that f(x+y) = f(x)+F(y) for all values of x and y. Which of the following statements must be true when a = b?</p>

<p>I. f(a+b) = 2f(a)
II. f(a+b) = [f(a)]^2
III. f(b) + f(b) = f(2a)
The answer is I and III</p>

<p>pg 519 #20</p>

<p>This is a diagram one, if you dont have the book and would like to solve it I'll post it.</p>

<p>pg 530 #17</p>

<p>This is also a diagram. It's the notched edge problem:</p>

<p>-80 inch long paper strip
-notch was made by removing a 1 inch per side equilateral triangle from each 4 inch length
-total length of the notched edges
The answer is 100</p>

2

<p>16) </p>

<p>1x2x3 = 3
2x3x4
.
.
.
9x10x11 = 990</p>

<p>So 9 integers.</p>

<p>19)</p>

<p>I. f(a+b) = 2f(a) is true because
f(a+b) = f(a) + f(b) = f(a) + f(a) = 2f(a)</p>

<p>II. f(a+b) = [f(a)]^2 is not true (refer to above)</p>

<p>III. f(b) + f(b) = f(2a) is true because
f(b) + f(b) = f(b+b) = f(a+a) = f(2a)</p>

<p>Don’t have a book for the others, sorry.</p>

3

<ol>
<li> Look at each 4 inch section. There are 2o of them all together on the 80 inch strip. Each of them has a 1 inch section replaced with a 2 inch section (the triangular cutout) increasing the length that section from 4 to 5. So now there are 20 5-inch sections for a total length of 100.</li>
</ol>