Mixed Topic Worksheet Grades 8/9: Day 024
- 1
Question 1. Matthew says that 3√20 is greater than 2√45. Is Matthew correct? Show your working.
Simplifying Surds▶ Show worked answerHide worked answer
- M1: 3√20 = 3√4 × 5 = 6√5
- M1: 2√45 = 2√9 × 5 = 6√5
- A1: Not correct, they are equal
Answer: No. Both are equal to 6√5[3 marks] - 2
Question 2. Solve 3cos x + 2 = 0 for 0^° ≤ x ≤ 360^°. Give your answers correct to 1 decimal place
Solving Trigonometric Equations Using a Graph▶ Show worked answerHide worked answer
- M1: cos x = -dfrac23, so x = cos⁻¹≤ft(-dfrac23)
- M1: 360^° - 131.8^°
- A1: 131.8^° and 228.2^°
Answer: x = 131.8^° and x = 228.2^°[3 marks] - 3
Question 3. Solve x² - 5x - 1 = 0 by completing the square. Give your solutions to 2 decimal places.
Solving Quadratics by Completing the Square (a = 1)▶ Show worked answerHide worked answer
- M1: ≤ft(x - frac52)² = 1 + 25/4
- M1: x = frac52 ± frac√292
- A1: x = 5.19 or x = -0.19
Answer: x = 5.19 or x = -0.19[3 marks] - 4
Question 4. The curve y = x² - 5 meets the line y = 4x at two points
Work out the coordinates of both pointsSolving Quadratic Simultaneous Equations▶ Show worked answerHide worked answer
- M1: x² - 5 = 4x so x² - 4x - 5 = 0
- M1: (x - 5)(x + 1) = 0
- A2: (5, 20) and (-1, -4)
Answer: (5, 20) and (-1, -4)[4 marks] - 5
Question 5. The inequality x² - 4x + k > 0 is true for every value of x
Find the possible values of kSketching Quadratic Inequalities▶ Show worked answerHide worked answer
- M1: completes the square, x² - 4x + k = (x - 2)² + k - 4
- M1: the smallest value of the expression is k - 4, which must be greater than 0
- A1: k > 4
Answer: k > 4[3 marks]
Mixed Topic Worksheet Grades 8/9: Day 024
- 1
Question 1. Matthew says that 3√20 is greater than 2√45. Is Matthew correct? Show your working.
[3 marks]Simplifying Surds▶ Show worked answerHide worked answer
- M1: 3√20 = 3√4 × 5 = 6√5
- M1: 2√45 = 2√9 × 5 = 6√5
- A1: Not correct, they are equal
Answer: No. Both are equal to 6√5 - 2
Question 2. Solve 3cos x + 2 = 0 for 0^° ≤ x ≤ 360^°. Give your answers correct to 1 decimal place
[3 marks]Solving Trigonometric Equations Using a Graph▶ Show worked answerHide worked answer
- M1: cos x = -dfrac23, so x = cos⁻¹≤ft(-dfrac23)
- M1: 360^° - 131.8^°
- A1: 131.8^° and 228.2^°
Answer: x = 131.8^° and x = 228.2^° - 3
Question 3. Solve x² - 5x - 1 = 0 by completing the square. Give your solutions to 2 decimal places.
[3 marks]Solving Quadratics by Completing the Square (a = 1)▶ Show worked answerHide worked answer
- M1: ≤ft(x - frac52)² = 1 + 25/4
- M1: x = frac52 ± frac√292
- A1: x = 5.19 or x = -0.19
Answer: x = 5.19 or x = -0.19 - 4
Question 4. The curve y = x² - 5 meets the line y = 4x at two points
[4 marks]
Work out the coordinates of both pointsSolving Quadratic Simultaneous Equations▶ Show worked answerHide worked answer
- M1: x² - 5 = 4x so x² - 4x - 5 = 0
- M1: (x - 5)(x + 1) = 0
- A2: (5, 20) and (-1, -4)
Answer: (5, 20) and (-1, -4) - 5
Question 5. The inequality x² - 4x + k > 0 is true for every value of x
[3 marks]
Find the possible values of kSketching Quadratic Inequalities▶ Show worked answerHide worked answer
- M1: completes the square, x² - 4x + k = (x - 2)² + k - 4
- M1: the smallest value of the expression is k - 4, which must be greater than 0
- A1: k > 4
Answer: k > 4
Mixed Topic Worksheet Grades 8/9: Day 024
- 1
Question 1. Matthew says that 3√20 is greater than 2√45. Is Matthew correct? Show your working.
Simplifying Surds▶ Show worked answerHide worked answer
- M1: 3√20 = 3√4 × 5 = 6√5
- M1: 2√45 = 2√9 × 5 = 6√5
- A1: Not correct, they are equal
Answer: No. Both are equal to 6√5[3 marks] - 2
Question 2. Solve 3cos x + 2 = 0 for 0^° ≤ x ≤ 360^°. Give your answers correct to 1 decimal place
Solving Trigonometric Equations Using a Graph▶ Show worked answerHide worked answer
- M1: cos x = -dfrac23, so x = cos⁻¹≤ft(-dfrac23)
- M1: 360^° - 131.8^°
- A1: 131.8^° and 228.2^°
Answer: x = 131.8^° and x = 228.2^°[3 marks] - 3
Question 3. Solve x² - 5x - 1 = 0 by completing the square. Give your solutions to 2 decimal places.
Solving Quadratics by Completing the Square (a = 1)▶ Show worked answerHide worked answer
- M1: ≤ft(x - frac52)² = 1 + 25/4
- M1: x = frac52 ± frac√292
- A1: x = 5.19 or x = -0.19
Answer: x = 5.19 or x = -0.19[3 marks] - 4
Question 4. The curve y = x² - 5 meets the line y = 4x at two points
Work out the coordinates of both pointsSolving Quadratic Simultaneous Equations▶ Show worked answerHide worked answer
- M1: x² - 5 = 4x so x² - 4x - 5 = 0
- M1: (x - 5)(x + 1) = 0
- A2: (5, 20) and (-1, -4)
Answer: (5, 20) and (-1, -4)[4 marks] - 5
Question 5. The inequality x² - 4x + k > 0 is true for every value of x
Find the possible values of kSketching Quadratic Inequalities▶ Show worked answerHide worked answer
- M1: completes the square, x² - 4x + k = (x - 2)² + k - 4
- M1: the smallest value of the expression is k - 4, which must be greater than 0
- A1: k > 4
Answer: k > 4[3 marks]