Here I offer a complete Lesson on maths A level suitable to Edexcel C1 Differentiation. This set of notes completely covers the subject with 50 worked examples. With over 20 years experience in teaching O level and A Level mathematics(Pure and Mechanics) I offer this set of notes covering a wide range of problems with complete solutions.In this way I hope to help students achieve a high score in their A Level Maths examinations. Each Lesson covers theory and formula necessary for the chapter and step by step explanation to all solutions. Problems are arranged in an ascending order of difficulty reaching A level standard. The aim is to show students as many worked examples as possible which is not practical to see either in class or a personal tutor. Applies also for any students studying at this level. It includes: 1) Differentiation of the form y=kx, y=ax DEGREESn 2) First derivatives, Second derivatives. 3) Gradients of tangents, and normals. 4) Equations of tangents and normals to a curve.