ACC AAF W/S #4 Key

1. ACCUPLACER® Module #3 - AAF Worksheet #4 - Key 1

2. Module #3 Worksheet #4 1. C: The equation x = 3 is not a function because it does not pass the vertical line test. This test is made from the definition of a function, where each x-value must be mapped to one and only one y-value. This equation is a vertical line, so the x- value is mapped with an infinite number of y-values. 2. A: The function can be factored to identify the zeros. First, the term 3x is factored out to the front because each term contains 3x. Then the quadratic is factored into (x + 3) (x - 2). 3. D: Finding the slope of a line tangent to the given function involves taking the derivative twice. The first derivative gives the line tangent to the graph. The second derivative finds the slope of that line. The line tangent to the graph has an equation y' = 3x2. The slope of the line at x = 2 is found by the second derivative, y = 6x, or y = 6(2) = 12. 4. A: This answer is correct because (2 + 2i) (2 - 2i), using the FOIL method and rules for imaginary numbers, is: 4 - 4i + 4 -4i2 = 8. Choice B is not the answer because there is no i in the final answer, since the i's cancel out in the FOIL. Choice C, 4, is not the final answer because we add 4 + 4 in the end to equal 8. Choice D, 4i, is not the final answer because there is neither a 4 nor an i in the final answer. 5. D: Multiply the top and bottom by (2 + 2i), the conjugate, to arrive at 8 NAME: _____KEY_________________ i, which 8 cancels to i. Choice A is not the answer because the 8's cancel out. Choice B is not the answer because the 8'scancel out. Choice C is not the answer because 2 is not left, but 8 is. 2