Evaluating Quadratic Functions.pptxEvaluating Quadratic Functions.pptx
- 1. Grade 10 Mathematics Evaluating Quadratic Functions Open Notes Quiz Teacher Sari Purdue
- 2. Quiz Reminders 1. Have your whiteboard and markers ready. 2. Teacher will flash the question on the screen. 3. Write your answer on the whiteboard. 4. Take a picture of your solution and send the image through a private message. 5. You have 2 minutes to send your solution before proceeding to the next question. 6. Notes are allowed to be browsed during this activity.
- 4. Which of the following is not a quadratic function? f(x) = 2 3x 4 f(x) = x - 3x + 1 2 f(x) = 2x + 4 a) b) c) Question #1
- 5. Which of the following is true about a quadratic function? a) it should have an inequality symbol b) the highest degree is 2 c) the literal coefficients may have negative exponents Question #2
- 6. How many zeroes does the function f(x) = x - 3x + 2 have? 2 a) 2 b) 1 c) 0 Question #3
- 7. Evaluate the function if x = 0 f(x) = x - 2x + 1 2 Question #4
- 8. f(x) = x + 3x - 6 2 Question #5 Evaluate the function if x = 1
- 9. f(x) = 3x + 8x - 7 2 Question #6 Evaluate the function if x = 2
- 10. Given this function, what is the value of f(- 3)? f(x) = -x - 2x + 4 2 Question #7
- 11. f(x) = 2(x + 5) 2 Question #8 Given this function, what is the value of f(2)?
- 12. Question #9 Given this function, find the value of f(1) - f(-1). f(x) = x(x - 2) + 18
- 13. f(x) = (x + 1) 2 Question #10 Given this function, find the value of f(3) + f(2).
- 14. Answer Key
- 15. Question #1 Question #2 Question #3 Which of following is not a quadratic function? Which of following is true about quardratic function? To find the zero of the function, equate the right expression to zero This means that x - 2 = 0 or x - 1 = 0 which also equivalent to x = 2 or x = 1. The zeroes of f(x) = x - 3x + 2 are 1 and 2. Therefore, the function has 2 zeroes Letter a The degree of f(x) = 2x + 4 is 1 making it a linear function and not a quadratic function. Letter b. Letter a and c and c are not correct answers because a quadratic function is an equality and its literal coefficients or variables should be a positive integer. Letter a Factor ⟹ x - 3x + 2 = 0 ⟹ (x - 2)(x - 1) = 0 How many zeroes does the function f(x) = x - 3x + 2 have? 2 f(x) = x - 3x + 2 2 2 2
- 16. Substitute 0 to x in the function Substitute 1 to x in the function Simplify Simplify f(x) = x + 3x - 6 = 0 + 0 + 1 = 1 + 3 - 6 = 1 = -2 2 f(x) = x - 2x + 1 2 ⟹ f(0) = 0 - 2(0) + 1 2 ⟹ f(1) = 1 + 3(1) - 6 2 Question #4 Question #5
- 17. Substitute 2 to x in the function Substitute 2 to x in the function Substitute -3 to x in the function Simplify Simplify terms inside the parentheses Simplify Simplify f(x) = 3x + 8x - 7 f(-3) means that x = -3 = 3(4) + 16 - 7 = 2(4 + 5) = 2(9) = 18 = 12 + 9 = -9 + 6 + 4 = 1 ⟹ f(2) = 3(2) + 8(2) - 7 f(x) = x - 2x + 4 2 2 ⟹ f(2) = 2 ((2) + 5) 2 2 ⟹ f(-3) = -(-3) - 2(-3) + 4 2 f(2) means that x = 2 Question #8 Question #6 Question #7 f(x) = 2(x + 5) 2 = 21
- 18. Substitute 1 to x in the function Substitute -1 to x in the function Simplify Simplify ⟹ f(1) = 1(1 - 2) + 18 ⟹ f(-1) = -1 (-1 - 2) + 18 = -1 + 18 = 3 + 18 = 17 = 21 f(x) = x(x - 2) + 18 f(x) = x(x - 2) + 18 If f(1) = 17 & f(-1) = 21, then f(1) - f(-1) = 17 - 21 = -4 Step 1. Find the values of f(1) & f(-1) Step 2. Find f(1) - f(-1) based on the values obtained from the prevision computation. Question #9
- 19. Question #10 Substitute 3 to x in the function Substitute 2 to x in the function Square Square = 16 = 9 f(x) = (x + 1) Step 1. Find the values of f(3)& f(2) = 4 2 2 ⟹ f(2) = (2 + 1) 2 = 3 2 If f(3) = 16 & f(2) = 9, then f(3) + f(2) = 16 + 9 = 25 Step 2. Find f(3) + f(2) based on the values obtained from the previous computation. f(x) = (x + 1) 2 ⟹ f(3) = (3 + 1) 2
- 20. See you on our next session: Word Problems involving Quadratic Functions Good Job!