Question

Divide –2x³ + 21x² – 20x – 12 by (x – 3).  (2 points)

Answer 1

x^3__x^2__x^1__x^0 | 3
---------------------------------------...
-2___21__-20__-12
____-6___45___75
-2__15___25___63

Therefore: -2x^3 + 21x^2 -20x -12 = (x-3) * ( -2x^2 + 15x + 25) + 63


2. Let y = (3 - 4x)^2 , this function's domain is the set of real numbers and its range is the set of all non-negative numbers. f-1 exists if for any given y in f's range, solving for x gives a unique x:

y = (3 - 4x)^2 <=> sqrt(y) = abs(3 - 4x) <=>
<=> 3 - 4x = sqrt(y) OR 3 - 4x = -sqrt(y) <=>
<=> x = [ 3 - sqrt(y) ] / 4 OR x = [ 3 + sqrt(y) ] / 4

Since for every y>0 x is not well defined, f-1 does not exist
(x is well defined only for y = 0)

Answer 2

what?

Answer 3

http://openstudy.com/study#/updates/52d8e0d9e4b02397b18e1abf