Here I offer a complete Lesson on maths A Level suitable to Edexcel C3 Differentiation. This set of notes completely covers the chapter with 97 worked examples.With over 20 years experience in teaching A level mathematics(Pure Mathematics and Mechanics) I offer this notes covering a wide range of problems with complete solutions.Each lesson covers theory and formula necessary for the chapter and step by step explanation of all solutions. Problems are arranged in an ascending order of difficulty reaching A level standard. Applies also for any students studying at this level. It includes: a) Trigonometric Differentiation ie of sinx, cosx, tanx, cotx, secx, cosecx. b) General case of trigonometric differentiation of y=sinf(x), y=cosf(x)... etc. c) Differentiation of powers, such as: y=(ax+b) DEGREESn d) differentiation of square roots e) Differentiation of y=e DEGREES(x). Differentiation of the general case y=e DEGREES f(x)]. Differentiation of the case y=e DEGREES(kx). f) Differentiation of the case y=lnx. Differentiation of the general case y=lnf(x). g) Differentiating products(U.V), use of product rule. h) Differentiating quotients(U/V), use of quotient rule. i) Proving of results used. ie prove that dy/dx of y=tanx is... j) Equations of tangents and normals to curves k) Problems involving differentiation ie rates of change..