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Differentiation formulae
The 7 results the differentiation notes display, each with the conditions it needs to be true and a link to the lesson that states it. Of the 7, the formulae booklet prints 2, 4 are yours to memorise and 1 is a working line the notes derive in front of you.
Years 12-13 · 5 lessons with formulae.
A result the Edexcel formulae booklet prints is marked as such; one it does not print is marked to learn; and a result badged derived in the lesson is a working line the notes build in front of you rather than a standard result to memorise.
f'(x) = limh → 0 f(x + h) − f(x)hf′(x) = lim_(h → 0) ((f(x + h) − f(x))/h) IN THE FORMULAE BOOKLETConditionsThe limit must exist, which is what it means for f to be differentiable at x.
y = xn ⇒ dydx = nxn−1y = x^n ⇒ dy/dx = nx^(n − 1) NOT IN THE BOOKLET: LEARN ITConditionsAny real n, with x ≠ 0 when n is negative and x > 0 where a non-integer power needs it.
sin kx → kcos kx, cos kx → −ksin kxsin kx → k cos kx, cos kx → − k sin kx NOT IN THE BOOKLET: LEARN ITConditionsx in radians. Both derivatives are wrong in degrees. ekx → kekx, ln x → 1xe^kx → ke^kx, ln x → 1/x NOT IN THE BOOKLET: LEARN ITConditionsln x needs x > 0.
dydx = dydu × dudxdy/dx = dy/du × du/dx NOT IN THE BOOKLET: LEARN ITConditionsy differentiable in u and u differentiable in x. (uv)' = u'v − uv'v2(u/v)′ = (u′v − uv′)/v^2 IN THE FORMULAE BOOKLETConditionsu and v differentiable, and v ≠ 0.
dydx = 1dx/dy = 1cos ydy/dx = 1/(dx/dy) = 1/cos y NOT IN THE BOOKLET: DERIVED IN THE LESSONConditionsdx/dy must be non-zero and finite; here that means cos y ≠ 0.
Every formula in the library is indexed by unit on the equation index, and the differentiation notes are where these results are derived and used. The 4 the booklet does not print are on the list of every formula to memorise, alongside the rest of the course.
Also: Exponentials and logarithms formulae · Integration formulae