Expand the brackets, then find dy/dx for y = (x + 5)(x - 3).
(Total for Question 9 is 2 marks)
10
Expand the brackets, then find dy/dx for y = (3x - 2)(2x + 1).
(Total for Question 10 is 2 marks)
11
A curve has equation y = x3 - 5x + 2. Calculate the gradient of the curve at the point where x = 3.
(Total for Question 11 is 2 marks)
12
A curve has equation y = 2x2 + 3x - 7. Calculate the gradient of the curve at the point where x = -2.
(Total for Question 12 is 2 marks)
13
A curve has equation y = x2 - 10x + 3. Find the value of x for which the gradient of the curve is 4.
(Total for Question 13 is 3 marks)
14
The curve C has equation y = x3 - 5x2 + 2x - 1. Show that the gradient of C at the point where x = 4 is 10.
(Total for Question 14 is 3 marks)
15
A curve has equation y = x2 - 3x + 8. Find the equation of the tangent to the curve at the point where x = 5.
(Total for Question 15 is 4 marks)
16
A curve has equation y = x3 - 3x2 - 24x + 5. Find the coordinates of the stationary points of the curve.
(Total for Question 16 is 4 marks)
17
A curve has equation y = x3 + 9x2 + 28x - 3. Show that this curve is an increasing function for all values of x.
(Total for Question 17 is 4 marks)
18
A framer is making a rectangular picture frame from a single length of moulding 100 cm long, bent to form all four outer edges of the frame. Let x cm be the width of the frame and let A cm2 be the area enclosed by the frame.
(a)Show that A = 50x - x2.(2)
(b)Find the value of x that gives the maximum area, and calculate this maximum area.(2)
(Total for Question 18 is 4 marks)
Mark scheme · C1D Differentiation of Polynomials: Fluency and Exam Drill
Question 1
B1 dy/dx = 6x5 cao
Answer: dy/dx = 6x5
Question 2
B1 dy/dx = 4x3 cao
Answer: dy/dx = 4x3
Question 3
B1 dy/dx = 15x2 cao
Answer: dy/dx = 15x2
Question 4
B1 dy/dx = 6 cao
Answer: dy/dx = 6
Question 5
B1 dy/dx = 0 cao
Answer: dy/dx = 0
Question 6
B1 dy/dx = 15x4 cao
Answer: dy/dx = 15x4
Question 7
M1 differentiates at least two terms correctly (e.g. 6x2 and -10x seen)
A1 dy/dx = 6x2 - 10x + 4 cao
Answer: dy/dx = 6x2 - 10x + 4
Question 8
M1 differentiates at least two terms correctly (e.g. 4x3 and 9x2 seen)
A1 dy/dx = 4x3 + 9x2 - 2 cao
Answer: dy/dx = 4x3 + 9x2 - 2
Question 9
M1 expands brackets to obtain y = x2 + 2x - 15 oe
A1 dy/dx = 2x + 2 cao ft from expansion
Answer: dy/dx = 2x + 2
Question 10
M1 expands brackets to obtain y = 6x2 - x - 2 oe
A1 dy/dx = 12x - 1 cao ft from expansion
Answer: dy/dx = 12x - 1
Question 11
M1 differentiates to obtain dy/dx = 3x2 - 5 and substitutes x = 3
A1 gradient = 22 cao
Answer: gradient = 22
Question 12
M1 differentiates to obtain dy/dx = 4x + 3 and substitutes x = -2