Differentiation

Differentiation is used to caculate rate of change on a gradient of tangent to a curve with the function of change in x is a change in y that can be seen as (dy/dx). For example, the change of velocity in acceleration

Differentiate a function rules (Sacchetti S., 2024)
Rules Formula Explain Example 1 Example 2
Constant Rule $$\frac{d}{dx} c = 0$$ Any number(indicated with "c") without a x axis is equal to zero $$10 ==> 0$$ $$69 ==> 0$$
Power Rule $$\frac{d}{dx}xⁿ = nx^{n-1}$$ When x axis has power, time number of power to x and remove a power from x $$x^2 ==> 2x$$ $$2x^4 ==> 8x^3$$
Trigonometric Rules $$\frac{d}{dx} \sin(x) = cos(x)$$ Sin turns into cos $$\sin(5) ==> \cos(5)$$ $$\sin(45) ==> \cos(45)$$
Trigonometric Rules $$\frac{d}{dx} \cos(x) = -sin(x)$$ Cos turns into -sin $$\cos(5) ==> -\sin(5)$$ $$\cos(45) ==> -\sin(45)$$
Exponential Rules $$\frac{d}{dx} b^x = b^x\ln(b)$$ Exponential turns into log $$\frac{d}{dx} b^5 = b^5\ln(b) $$ $$\frac{d}{dx} b^45 = b^4\ln(b) $$
Logarithmic Rules $$\frac{d}{dx} \ln(x) = \frac{1}{x}$$ Log turns into fraction x of 1 $$\frac{d}{dx} \ln(5) = \frac{1}{5}$$ $$\frac{d}{dx} \ln(45) = \frac{1}{45}$$

Differentiation Video

Click to find the referance (The Organic Chemistry Tutor)

Example

Example 1, differentiate and find any stationary points of y = x³ - 6x² + 9x + 1.

Using the power rule (d/dx * xⁿ = nxⁿ⁻¹ )
x³ - 6x² + 9x ===> 3x² - 12x + 9
and the constant rule(d/dx *c = 0)
1 ===> 0

now factorise to make x = 0 (there many methods to solve this, but quadratic is one of the a reliable ways. Due to the question being easy, I will not be using it)
3x² - 12x + 9
divide all by 3 to make 3x² on it own
x² - 4x + 3
-1 and -3 are the factors because when added together they make -4 and when time, they makes 3
(x - 1)(x - 3)
Slove for x by moving them to the other side
x - 1 = 0 ===> x = 1 and x - 3 = 0 ===> x = 3

∴ there is a MAXIMA at x = 1 or 3
This can be seen in a graph below:

Click for exact equation = https://www.desmos.com/calculator/m3qoxoz7dz

Click to find the referance

The blue line represent x = 1 because that was the highest point in that curve so the black line represent x = 3 due to lowest point in that curve

Random questions with answers

test


test


You don't have to stop when you have done it once, you can keep doing it mutiple times

$$ y = \sin(x): \frac{dy}{dx} = \cos(x), \frac{d^2y}{dx^2} = -\sin(x), \frac{d^3y}{dx^3} = -\cos(x), \frac{d^4y}{dx^4} = \sin$$

There is a power depending on how many times you have done it on thr top d and x

There are quiz at https://www.bbc.co.uk/bitesize/guides/zyj77ty/test

Click for referance(bitesize)