Search our library of A Level questions

Top answers

All subjects

A Level

To what extent do males and females display cooperation and competition in same sex interactions to prove dominance?

Over many years, language has been categorised on the basis of gender suggesting that 'Men are from Mars and Women are from Venus'; a view adopted by John Gray. Difference theorists like Jane Pilkington a...

Answered by Hawa J. • English Language tutor

8616 Views

Show that: [sin(2a)] / [1+cos(2a)] = tan(a)

We start by expanding out the double trigonometric terms (sin(2a)) using the double angle formula, giving us: [2sin(a)cos(a)] / [1+cos^2(a) - sin^2(a)]. Next we spot that on the denominator (bottom half o...

Answered by George H. • Maths tutor

9489 Views

Why doesn't chlorine form hydrogen bonds even though it is more electronegative than nitrogen?

Chlorine has a higher electronegativity, but as it has a large atomic radius the electron density is spread out over a large area. This means that the electron density is too low to form proper hydrogen b...

Answered by Callum L. • Chemistry tutor

18171 Views

What does it mean when I get a negative value when I do a definite integral?

The definite integral gives the value of the area bounded between the curve at the given limits, and the x-axis (if we are integrating with respect to x!) If this value is negative, it means that the area...

Answered by Callum L. • Maths tutor

16146 Views