Search our library of A Level questions

Top answers

All subjects

A Level

How was the quadratic formula obtained.

We want a solution to ax^2+bx+c=0. Complete the square to get a[(x+b/2a)^2 -(b^2)/(4a^2)]+c=0. Expalding brackets and rearanging gets a(x+b/2a)^2=(b^2)/4a -c. Divide by a to get (x+b/2a)^2= b^2/4a^2 -c/a=...

Answered by Jon H. • Maths tutor

3740 Views

How many hours revision should I do between now and my exam? Can I have help coming up with a plan?

Let’s break this down. Let’s look at how much time you have before the exam and work out something manageable, because overwhelming yourself with too much revision can be counter productive.

Answered by Rose M. • English Literature tutor

4524 Views

Outline the Knowledge Argument for the nature of the mind

The knowledge argument purports to show that the human mind is not a physical thing by showing that no amount of physical information can capture all the information there is about it. It invites us to co...

Answered by Eno A. • Philosophy tutor

2464 Views

Contrast the processes of facilitated diffusion and active transport. (3 marks)

Key Points: 1) Active transport requires energy in the form of ATP whereas facilitated diffusion does not require energy; it is a passive process 2) Active transport can move molec...

Answered by Grace P. • Biology tutor

13578 Views

What happens in the cardiac cycle?

The cardiac cycle is driven by the myocytes in the heart, which are a special type of muscle tissue which are able to contract without input from the nervous system. This starts with a tissue called the S...

Answered by Eleanor J. • Biology tutor

2916 Views