Mixed Topic Worksheet Grades 8/9: Day 072
- 1
Question 1. Frequency densities: 0 < t ≤ 10 is 3, 10 < t ≤ 30 is 2.5, 30 < t ≤ 40 is 2. Work out an estimate for the median.
Median from a Histogram▶ Show worked answerHide worked answer
- M1: frequencies 30, 50, 20; the 50th value is 20 into the second class
- A1: 10 + 20/50 × 20 = 18
Answer: 18[2 marks] - 2
Question 2. A cone has a base radius of 5 cm and a slant height of 13 cm. Work out the angle between the slant height and the base. Give your answer correct to 1 decimal place.
3D Trigonometry▶ Show worked answerHide worked answer
- M1: cosθ = 5/13
- A1: 67.4°
Answer: 67.4°[2 marks] - 3
Question 3. Simplify fully dfracx² - 9x + 2 × dfracx² - 4x + 3
Multiplying & Dividing Algebraic Fractions▶ Show worked answerHide worked answer
- M1: dfrac(x - 3)(x + 3)x + 2 × dfrac(x - 2)(x + 2)x + 3
- M1: cancel (x + 3) and (x + 2)
- A1: (x - 3)(x - 2)
Answer: (x - 3)(x - 2)[3 marks] - 4
Question 4. A rectangle has width x cm and length (x + 6) cm
The area of the rectangle is 25 cm²
Use completing the square to work out the value of x
Give your answer correct to 3 significant figures.Solving Quadratics by Completing the Square (a = 1)▶ Show worked answerHide worked answer
- M1: x(x + 6) = 25 so x² + 6x - 25 = 0
- M1: (x + 3)² - 9 - 25 = 0
- M1: (x + 3)² = 34
- M1: x + 3 = ±√34
- A1: x = 2.83 (x = -8.83 rejected as a width cannot be negative)
Answer: x = 2.83[5 marks] - 5
Question 5. Write 3 - 12x - 2x² in the form a(x + p)² + q
Solving Quadratics by Completing the Square (a > 1)▶ Show worked answerHide worked answer
- M1: -2(x² + 6x) + 3
- M1: -2≤ft((x + 3)² - 9) + 3
- A1: -2(x + 3)² + 21
Answer: -2(x + 3)² + 21[3 marks]
Mixed Topic Worksheet Grades 8/9: Day 072
- 1
Question 1. Frequency densities: 0 < t ≤ 10 is 3, 10 < t ≤ 30 is 2.5, 30 < t ≤ 40 is 2. Work out an estimate for the median.
[2 marks]Median from a Histogram▶ Show worked answerHide worked answer
- M1: frequencies 30, 50, 20; the 50th value is 20 into the second class
- A1: 10 + 20/50 × 20 = 18
Answer: 18 - 2
Question 2. A cone has a base radius of 5 cm and a slant height of 13 cm. Work out the angle between the slant height and the base. Give your answer correct to 1 decimal place.
[2 marks]3D Trigonometry▶ Show worked answerHide worked answer
- M1: cosθ = 5/13
- A1: 67.4°
Answer: 67.4° - 3
Question 3. Simplify fully dfracx² - 9x + 2 × dfracx² - 4x + 3
[3 marks]Multiplying & Dividing Algebraic Fractions▶ Show worked answerHide worked answer
- M1: dfrac(x - 3)(x + 3)x + 2 × dfrac(x - 2)(x + 2)x + 3
- M1: cancel (x + 3) and (x + 2)
- A1: (x - 3)(x - 2)
Answer: (x - 3)(x - 2) - 4
Question 4. A rectangle has width x cm and length (x + 6) cm
[5 marks]
The area of the rectangle is 25 cm²
Use completing the square to work out the value of x
Give your answer correct to 3 significant figures.Solving Quadratics by Completing the Square (a = 1)▶ Show worked answerHide worked answer
- M1: x(x + 6) = 25 so x² + 6x - 25 = 0
- M1: (x + 3)² - 9 - 25 = 0
- M1: (x + 3)² = 34
- M1: x + 3 = ±√34
- A1: x = 2.83 (x = -8.83 rejected as a width cannot be negative)
Answer: x = 2.83 - 5
Question 5. Write 3 - 12x - 2x² in the form a(x + p)² + q
[3 marks]Solving Quadratics by Completing the Square (a > 1)▶ Show worked answerHide worked answer
- M1: -2(x² + 6x) + 3
- M1: -2≤ft((x + 3)² - 9) + 3
- A1: -2(x + 3)² + 21
Answer: -2(x + 3)² + 21
Mixed Topic Worksheet Grades 8/9: Day 072
- 1
Question 1. Frequency densities: 0 < t ≤ 10 is 3, 10 < t ≤ 30 is 2.5, 30 < t ≤ 40 is 2. Work out an estimate for the median.
Median from a Histogram▶ Show worked answerHide worked answer
- M1: frequencies 30, 50, 20; the 50th value is 20 into the second class
- A1: 10 + 20/50 × 20 = 18
Answer: 18[2 marks] - 2
Question 2. A cone has a base radius of 5 cm and a slant height of 13 cm. Work out the angle between the slant height and the base. Give your answer correct to 1 decimal place.
3D Trigonometry▶ Show worked answerHide worked answer
- M1: cosθ = 5/13
- A1: 67.4°
Answer: 67.4°[2 marks] - 3
Question 3. Simplify fully dfracx² - 9x + 2 × dfracx² - 4x + 3
Multiplying & Dividing Algebraic Fractions▶ Show worked answerHide worked answer
- M1: dfrac(x - 3)(x + 3)x + 2 × dfrac(x - 2)(x + 2)x + 3
- M1: cancel (x + 3) and (x + 2)
- A1: (x - 3)(x - 2)
Answer: (x - 3)(x - 2)[3 marks] - 4
Question 4. A rectangle has width x cm and length (x + 6) cm
The area of the rectangle is 25 cm²
Use completing the square to work out the value of x
Give your answer correct to 3 significant figures.Solving Quadratics by Completing the Square (a = 1)▶ Show worked answerHide worked answer
- M1: x(x + 6) = 25 so x² + 6x - 25 = 0
- M1: (x + 3)² - 9 - 25 = 0
- M1: (x + 3)² = 34
- M1: x + 3 = ±√34
- A1: x = 2.83 (x = -8.83 rejected as a width cannot be negative)
Answer: x = 2.83[5 marks] - 5
Question 5. Write 3 - 12x - 2x² in the form a(x + p)² + q
Solving Quadratics by Completing the Square (a > 1)▶ Show worked answerHide worked answer
- M1: -2(x² + 6x) + 3
- M1: -2≤ft((x + 3)² - 9) + 3
- A1: -2(x + 3)² + 21
Answer: -2(x + 3)² + 21[3 marks]