Review for Test IV – Sections 7.5,7.6,8.1-8.4 MAT135 1. Solve for x: Spring 2010 4 y 4 3 y 7 0 , where x is a real number. 2. Multiply and simplify: (6 8i)(3 9i) . 3. Solve: (3k 1) 2 9 1 . 4. Find the value of t such that z 2 8z t is a perfect square. 5. If f ( x) x 2 8 and g ( x) 8 x 11 find all value(s) of x such that f(x)=g(x). 6. Solve: x2 10x 4 0 . 7. Write the quadratic equation that has x 2, x 10 as solutions. 2 3 1 3 8. Solve for z: z 2 z 3 0 . 9. Use the discriminant to find the number and type of solutions for 4 x2 x 5 . 10. Find the vertex and domain and range of: f ( x) 3 x 2 18 x 5. 11. The temperature, t, in degrees Farenheit, of a chemical reaction is approximated by the function t ( s ) 3s 2 36s 70 where s is the number of seconds after the reaction begins. What is the lowest temperature attained by the reaction, and when will it occur? 12. Consider the function f ( x) x 2 9 x 20. Which statement(s) is/ are true? a. The roots occur at (4,0) and (5,0) . 9 1 2 4 b. The vertex is at ( , ) . c. The y-intercept is at (-20,0). d. The domain is (, ) . e. The graph is a parabola that opens upward. 13. Simplify: 5 Dugopolski 1 . 25 1 MAT135 Review for Test IV – Sections 7.5,7.6,8.1-8.4 Spring 2010 14. Solve: 2 x2 16 0 . 15. What is the range, in interval notation, of the function below? You may assume that each tick mark represents one unit. y x 16. Simplify: 18 72 . 6 17. Evaluate and simplify: (2 3i ) 2 . 18. Evaluate: 16( 5 16) . 19. Solve by completing the square: x2 6x 7 0 . 20. What is the vertex of the graph of the quadratic function f ( x) 2 x 2 4 x 1 ? Dugopolski 2 Review for Test IV – Sections 7.5,7.6,8.1-8.4 MAT135 Spring 2010 Answer Key 1) y = 3 2) 90 – 30i 3) k 1 2i 2 3 4) t = 16 5) x 4 13 6) x 5 21 7) 8) 9) 10) x 2 8 x 20 0 z = 27, z = – 1 2 complex numbers solutions ( 3, 22) , D ( , ) , R[22, ) 11) Lowest temp: – 38 ° occurs at 6 seconds 12) a) F b) T c) F d) T e) F 13) i 14) x 2i 2 15) (, 6] 16) 3 i 2 17) 12i – 5 18) 4 5 16 19) x 3 2 20) (1, 3) Dugopolski 3