Mathematics
Differentiation and its applications
- 1.
Differentiate y = x^2 e^(3x) with respect to x.
[3 marks] · no calculator - 2.
Find the gradient of the curve y = (3x^2 + 1)^4 at the point where x = 1.
[3 marks] · no calculator - 3.
Find the exact x-coordinates of the stationary points of y = (2x + 1)/(x^2 + 1).
[4 marks] · no calculator - 4.
The curve C has equation x^2 + xy + y^2 = 7 and passes through P(1, 2). Find the equation of the tangent to C at P in the form ax + by = c.
[5 marks] · no calculator - 5.
A closed cylinder has volume 500 cm^3. Find the radius that minimises its total surface area, and the minimum surface area, giving answers to 3 significant figures. Justify that it is a minimum.
[6 marks] - 6.
Air is pumped into a spherical balloon at 100 cm^3 per second. Find (a) the rate at which the radius increases when r = 5 cm, (b) the rate at which the surface area increases at that instant. [V = 4/3 pi r^3, S = 4 pi r^2]
[5 marks] · no calculator
Marking points are indicative, not an official mark scheme. Accept equivalent valid methods and supported interpretations that address the task; award each mark once without requiring the model wording.