Pre-Calc. PRACTICE! Chapter 1 Test Name_____________________ Hour ________ Non-Calculator Part 1 1. Find the domain of 9 x2 . Ans: 9 – x2 > 0 (3 – x)(3 + x) = 0 3 = x or -3 = x -3 y ( x 3) 5 2 x 3 - + 2. Find f (x) and g (x) so that the function y f g (x) . 3 D: (-3, 3) f ( x) x 5 2 x Ans: g ( x) x 3 Graph the functions in problems 3, 4, and 5 using the transformation rules and the ten basic functions. You must graph three points with your final graph! 3. f (x) 3 x 4 Start with (0, 0) (1, 1) Vertical stretch of 3 (0, 0) (1, 3) Right 4 (4, 0) (5, 3) g x 1 x3 2 5. Start with (-1, 1) (0, 0) (1, 1) Reflect over x-axis (-1, -1) (0, 0) (1, -1) 1 Vertical shrink of 2 1 1 (-1, 2 ) (0, 0) (1, 2 ) Left 3 1 2 4. h(x) -( 2 x +3) -2 You need to factor 1 out the 2 inside the function! 1 h(x) -( 2 (x +6))2 -2 Start with (-1, 1) (0, 0) (1, 1) Reflection over (x-axis) (-1, -1) (0, 0) (1, -1) Horiz. Stretch of 2 (-2, -1) (0, 0) (2, -1) Left 6 (-8, -1) (-6, 0) (-4, -1) Down 2 (-8, -3) (-6, -2) (-4, -3) 2 6. If f ( x) 5x 2 and g ( x) x 4 , find f g (x) and state its domain. Ans: f g x 5 x 4 2 5x 4 2 5x 20 2 5x 22 D: [4, ) 2 Pre-Calc. PRACTICE! Chapter 1 Test Name_____________________ Hour ________ 1 1 (-4, 2 ) (-3, 0) (-2, 2 ) 7. Eliminate the parameter for the parametric equations and simplify. 2 x t and y 3t 2t . Ans: x2 = t so y = 3(x2)2 – 2x2 y = 3x4 – 2x2 9. Find f 1 ( x) and its domain if f ( x) x 3 2 . 8. Describe the transformations of the graph of f ( x) 2 x 2 into g ( x) x 4 3 1 Ans: Vertical shrink of 2 Right 6 Up 3 Calculator Part 10. Is the function h( x) x cos x even, odd, or neither? Ans: Find the domain and range of the original. switch x and y, then solve for y. Switch the domain and range for the inverse. f ( x) x 3 2 D : 3, Ans: h( x) x cos( x) x cos(x) Therefore it is an odd function. (You can also see this from your calculator. I will not ask for an algebraic verification on this problem.) R : 0, x y 3 2 x2 y 3 ( x 2) 2 y 3 ( x 2) 2 3 y f 1 ( x) ( x 2) 2 3 D : 0, 11. Let domain. Ans: f ( x) y 6x x 4 . Find f 1 ( x) and state its 6x x 4 Switch x and y and resolve for y. 6y y4 x( y 4) 6 y x xy 4 x 6 y x 2 25 x2 9 Ans: The denominator cannot equal zero and the radicand must be greater than or equal to zero. 12. Find the domain and range of y x2 9 0 ( x 3)( x 3) 0 xy 6 y 4 x x( y 6) 4 x 4x f 1 ( x) x6 x 3,3 x 2 25 0 x 5x 5 0 Pre-Calc. PRACTICE! Chapter 1 Test Domain: (- , 6) U (6, ) Name_____________________ Hour ________ Plot the zeros and do the sign test. + -5 + 5 D : ,5 5, Since 3 or -3 are not in these intervals, we do not have to worry about them. 13. Determine whether the following function is bounded above, bounded below, bounded, or not bounded. g x 2 x 14. A circle is inscribed in a square of side s. Write the area of the circle as a function of s. Ans: 2 s Ans: bounded above The area of a circle is A r 2 . Since s 2r , s then r , and the area can be expressed as: 2 s A 2 s 2 A 4 x3 3 g ( x) 4 x and 4x 1 15. Verify that are inverses by showing f g ( x) x and f ( x) g f ( x) x 2 16. Find the endpoint of the parametric function if t y 2 0 t 4 and x 2t 5 and t 3. Ans: when t = 0 x = 2(0)2 – 5 = 0 – 5 = -5 0 0 0 y = 03 3 when t = 4 x = 2(4)2 – 5 = 32 – 5 = 27 Pre-Calc. PRACTICE! Chapter 1 Test 3 4x 1 3 3 3 4x 1 4x 1 4 x 1 f g ( x) 3 3 4 4 4x 1 4x 1 3 12 x 3 12 x 4x 1 x 12 12 4x 1 Name_____________________ Hour ________ 4 4 y = 43 7 4 so the ordered pairs are (-5, 0) and (27, 7 ). g f ( x) 3 3 x 3 x 3 4x 4 1 4 4x 4x 4x 3 3 3 x 4 x 12 4 x 12 3 4x 4x x 17. State all extrema for the function f x x 3 3x x 2 . Identify whether they are local or absolute. 18. . Find all asymptotes of the function 3x f ( x) 4 x . Ans: Graph and calculate any maximums or minimums in your calculator. Ans: horizontal asymptote: Compare the degree of the numerator with the degree of the denominator so y = -3 vertical asymptote: Is where the denominator equals zero so x = Local max: (-0.92, 3.02) Local min: (0.95, -0.28) Since the domain is restricted to 2, , there is a minimum where x = -2. To find it use your table to see what the point is. Absolute min: (-2, -2) 19. State the intervals on which the function x2 1 4 x 2 is increasing and decreasing. Ans: Find vertical and horizontal asymptotes. This will help with the intervals. 1 1 Increasing: [0, 2 ) U ( 2 , ) 1 1 Decreasing: (- , 2 ) U ( 2 , 0] 20. 4Is the following function continuous? If it is discontinuous, state whether it is removable, jump, or infinite discontinuity. g x x x Ans: Discontinuous, jump Pre-Calc. PRACTICE! Chapter 1 Test 21. The table to the right shows numbers of new packaged goods products introduced to the marketplace each year from 1986 to 1997. a. Find a linear regression for the data using 1980 as year zero. Ans: In the STAT, EDIT menu, enter the data. Then in the STAT, CALC menu, choose linreg(ax+b) On the home screen finish the expression specifying Linreg(ax + b) L1, L2,Y1 and hit enter. The equation y 1,164.05x 4,161.15 will automatically be entered into your Y = menu. b. Based on the regression line, approximately how many new products would be introduced in the year 2000? Ans: Use 20 for x since it is 20 years after 1980. The answer will be 27,442 products. Name_____________________ Hour ________ Year 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 New Products 12,436 14,254 13,421 13,382 15,879 15,401 15,886 17,363 21,986 20,808 24,486 25,261