Proof by Contradiction What is proof by contradiction? A proof by contradiction assumes the?opposite?result is true Then, through a series of logical steps, shows that this cannot be so How ...
Stationary Points & Turning Points What is the difference between a stationary point and a turning point? A?stationary point?is a point at which the?gradient function?is equal to zero The?tange...
Second Order Derivatives What is the second order derivative of a function? If you?differentiate?the?derivative?of a?function?(i.e. differentiate the function a second time) you get the?second orde...
Chain Rule What is the chain rule? How do I know when to use the chain rule? How do I use the chain rule? Are there any standard results for using chain rule? Exam Tip You should aim to be able to ...
Edexcel IGCSE Physics 復(fù)習(xí)筆記 2.1.3 Resistance Calculating Current, Resistance & Potential Difference Resistance is defined as the?opposition?to current: The higher the resistance of a ...
Edexcel IGCSE Physics 復(fù)習(xí)筆記 2.1.2 Voltage & Energy Voltage The terminals of a cell make one end of the circuit?positive?and the other?negative This sets up a?potential difference?acro...
Edexcel IGCSE Physics 復(fù)習(xí)筆記 2.1.1 Charge & Current Current Electric current is defined as?the rate of flow charge In other words, the size of an electric current is the amount of char...
Disproof by Counter Example What is disproof by counter-example? Disproof by counter-examples involves finding a value that does?not?work for the given statement That value is called a?count...
Edexcel IGCSE Physics 復(fù)習(xí)筆記 1.4.3 Centre of Gravity Centre of Gravity The centre of gravity of an object (sometimes called the centre of mass) is defined as: The point through which the weight o...
