Search our library of A Level questions

Top answers

All subjects

A Level

Sketch y = 9x – 4x^3, showing where the curve crosses the x axis.

First you should look at the equation and try and get a sense of the general shape of the graph. The highest power in here is a 3, so this is a cubic graph. The coefficient (number in front of the x^3) is...

Answered by Anais E. • Maths tutor

5563 Views

“Mao's ideology was the primary cause for the failure of the Great Leap Forward of 1958 to 1962.” Assess the validity of this view.

Getting started: This question is asking us to assess the validity of a particular view which means that we need to relate the interpretation to the evidence that we have, and assess how ...

Answered by Jacob F. • History tutor

3013 Views

You are given a clear solution that is either an alkene or an alkane. Describe a test using bromine water that you could use to determine whether it is an alkene or alkane solution.

1 mark : Indication that the solution and bromine water should be mixed together1 mark : Indicating that the bromine water will de-colourise / go colourless if the solution contains an alkeneOR 1 mark awa...

Answered by Noah H. • Chemistry tutor

2256 Views

Part a) Draw the mechanism of the attack of CN- on CH3COCH3 in the presence of HCN Part b) Explain why the product of this reaction does not rotate the plane of plane polarised light

Part a) 1 mark : Show the nucleophilic attack of CN- at the carbonyl forming the O-1 mark : Show the protonation of the O- via the deprotonation of HCNPart b)1 mark: Student has identified that the interm...

Answered by Noah H. • Chemistry tutor

3612 Views

How do you find the x co-ordinates of the stationary points of a curve with the equation y = 10x - 2x^2 - 2x^3

First to find the stationary points, you have to differentiate the equation of the curve y, to give you (dy/dx) = 10 - 4x - 6x^2After differentiating the equations, the points at which the curve is statio...

Answered by David M. • Maths tutor

3431 Views