Top answers


How do I predict the shape and bond angle of an molecule?

Electron pairs arrange themselves so they are as far apart as possible (electron pair repulsion theory). In a covalent compound, the number of electron pairs around the central atom determines the shape of t...
TT
Answered by Tolu T. Chemistry tutor
16956 Views

Was the Cold War in fact 'cold'?

The war that took place between 1945 and 1991 has been termed the 'Cold War', largely due to the fact that the two main agitators (The Soviet Union and The United States of America) never came into direct co...
IS
Answered by Imogen S. History tutor
13267 Views

Finding stationary points

Finding stationary points. You can find stationary points on a curve by differentiating the equation of the curve and finding the points at which the gradient function is equal to 0. One way of determining a...
JF
Answered by Jessica F. Maths tutor
15082 Views

When do I use a cosine rule over a sine rule?

Both the sine and the consine rule applies to any triangle, you do not necessary need a right angle! You can usually use the cosine rule when you are given two sides and the included angle (SAS) or when you ...
JF
Answered by Jessica F. Maths tutor
128919 Views

How do you integrate xcos(x)?

Using integration by parts: split xcos(x) into x multiplied by cos(x). Differentiating x gives 1 and integrating cos(x) gives sin(x). The integral of xcos(x) can therefore be rewritten as xsin(x) - integral ...
AB
Answered by Aleksandr B. Maths tutor
9050 Views