Question Bank

Official NZQA past exam questions • AS91578 Differentiation

With video explanations by infinityplusone

15 questions
Achievement
Differentiate y=tan(x2+1)y = \tan(x^2 + 1).

*You do not need to simplify your answer.*
Achievement
Find the gradient of the tangent to the function f(x)=ln(3xex)f(x)=\ln(3x-e^x) at the point where x=0x=0.
Find the xx values of any points of inflection on the graph of the function y=e(6x2)y = e^{(6 - x^2)}.

Show any derivatives that you need to find when solving this problem.
A curve is defined by the parametric equations:

x=5sintx = 5\sin t and y=3tanty = 3\tan t

Find the gradient of the normal to the curve at the point where t=π3t = \dfrac{\pi}{3}.

*Show any derivatives that you need to find when solving this problem.*
Excellence
A closed cylindrical tank is to have a surface area of 20 m220\ \mathrm{m}^2.

Find the radius the tank needs to have so that the volume it can hold is as large as possible.

*You do not have to prove that your solution gives the maximum volume.*

*Show any derivatives that you need to find when solving this problem.*
Achievement
\nDifferentiate y=πx23y = \sqrt[3]{\pi - x^2}.\n\n*You do not need to simplify your answer.*
Achievement
A curve has the equation y=(x32x)3y = (x^3 - 2x)^3.

Find the equation of the tangent to the curve at the point where x=1x = 1.

*Show any derivatives that you need to find when solving this problem.*
For what value of kk does the function f(x)=xexkxf(x)=x-e^x-\frac{k}{x} have a stationary point at x=1x=-1?

Show any derivatives that you need to find when solving this problem.
The graph below shows the function y=f(x)y = f(x).
Loading diagram...
For the function f(x)f(x) above:

(i) Find all the value(s) of xx that meet each of the following conditions:

1. f(x)=0f'(x) = 0

2. f(x)<0f''(x) < 0

3. f(x)f(x) is not differentiable

(ii) What is the value of f(1)f(-1)?

(iii) What is the value of limx3f(x)\lim_{x\to3} f(x)?

State clearly if the value does not exist.
Excellence
A copper sheet of width 24 cm is folded, as shown, to make spouting.

Cross-section:
Loading diagram...
Find angle θ\theta which gives the maximum cross-sectional area.

*You do not need to prove that you have found a maximum.*

*Show any derivatives that you need to find when solving this problem.*
Achievement
Differentiate y=sin(2x)x2y = \dfrac{\sin(2x)}{x^2}.

*You do not need to simplify your answer.*
Achievement
For the function f(x)=x+16x2f(x)=x+\dfrac{16}{x-2}, find the xx-values of any stationary points.

*You must use calculus and clearly show your working, including any derivatives you need to find when solving this problem.*