# Differentiation and Displacement, Velocity and Acceleration

Distance Distance is the magnitude of the total movement from the start point or a fixed point. Displacement The displacement of a moving position relative to a fixed point. Displacement gives both the distance and direction that a particle is from a fixed point. For example, a particle moves $5$ units forwards from […]

# Maxima and Minima with Trigonometric Functions

A trigonometric equation can model periodic motions. By differentiating these functions, we can solve problems relating to maxima (maximums) and minima (minimums).Remember that the following steps are used when solving a maximum or minimum problem. Example 1 The population of a colony of ants rises and falls according to the breeding season. The population can […]

# How to Express the Velocity and the Acceleration as Functions of Displacement and Time

If a particle the displacement gives $P$ moves in a straight line and its position function $x(t)$, then: $$x(t) \xrightarrow{\text{differentiate}}v(t)=\dfrac{dx}{dt}\xrightarrow{\text{differentiate}} a(t)=\dfrac{dv}{dt}=\dfrac{d^2x}{dt^2}$$ Sign Interpretation Suppose a particle $P$ moves in a straight line with displacement function $s(t)$ relative to an origin $O$. Its velocity function is $v(t)$, and its acceleration function is $a(t)$.The sign diagram is […]

# Inflection Points (Points of Inflection)

Horizontal (stationary) point of inflection (inflection point) If $x \lt a$, then $f'(x) \gt 0$ and $f^{\prime \prime}(x) \le 0 \rightarrow$ concave down.If $x = a$, then $f'(x) = 0$ and $f^{\prime \prime}(x) = 0 \rightarrow$ horizontal point inflection.If $x \gt a$, then $f'(x) \gt 0$ and $f^{\prime \prime}(x) \ge 0 \rightarrow$ concave up. The […]

# Turning Points and Nature

A function’s turning point is where $f'(x)=0$. A maximum turning point is a turning point where the curve is concave up (from increasing to decreasing ) and $f^{\prime}(x)=0$ at the point.$$\begin{array}{|c|c|c|} \hlinef^{\prime}(x) \gt 0 & f'(x) = 0 & f'(x) \lt 0 \\ \hline& \text{maximum} & \\\nearrow & & \searrow \\ \hline\end{array}$$A minimum […]

# Increasing Functions and Decreasing Functions

Increasing and Decreasing We can determine intervals where a curve increases or decreases by considering $f'(x)$ on the interval in question. Monotone (Monotonic) Increasing or Decreasing Many functions increase or decrease for all $x \in \mathbb{R}$. These functions are called either monotone (monotonic) increasing or monotone (monotonic) decreasing. $y=2^x$ is monotone (monotonic) increasing for all […]

# Finding the Normal Equations

A normal curve is a straight line passing through the point where the tangent touches the curve and is perpendicular (at right angles) to the tangent at that point. The gradient of the tangent to a curve is $m$, then the gradient of the normal is $\displaystyle -\dfrac{1}{m}$, as the product of the gradients of […]

# Finding Equations of Tangent Line

Consider a curve $y=f(x)$. A tangent to a curve is a straight line that touches the curve at a given point and represents the gradient of the curve at that point.If $A$ is the point with $x$-coordinate $a$, then the gradient of the tangent line to the curve at this point is $f'(a)$. The equation […]

# Higher Derivatives

Given a function $f(x)$, the derivative $f^{\prime}(x)$ is known as the first derivative.The second derivative of $f(x)$ is the derivative of $f^{\prime}(x)$, which is $f^{\prime \prime}(x)$ or the derivative of the first derivative.\displaystyle \begin{align}f^{\prime}(x) &= \dfrac{d}{dx}f(x) \\f^{\prime \prime}(x) &= \dfrac{d}{dx}f'(x) \\f^{(3)}(x) &= \dfrac{d}{dx}f^{\prime \prime}(x) \\f^{(4)}(x) &= \dfrac{d}{dx}f^{(3)}(x) \\&\cdots \\f^{(n)}(x) &= \dfrac{d}{dx}f^{(n-1)}(x) \\\end{align}We can […]

# Derivative of Trigonometric Functions

\large \displaystyle \begin{align}\dfrac{d}{dx}\sin{x} &= \cos{x} \\\dfrac{d}{dx}\cos{x} &= -\sin{x} \\\dfrac{d}{dx}\tan{x} &= \sec^2{x} \\\end{align} Example 1 Prove $\dfrac{d}{dx}\tan{x} = \sec^2{x}$ using $\dfrac{d}{dx}\sin{x} = \cos{x}$ and $\dfrac{d}{dx}\cos{x} = -\sin{x}$. \( \begin{align} \displaystyle \require{AMSsymbols} \require{AMSsymbols} \require{color}\dfrac{d}{dx}\tan{x} &= \dfrac{d}{dx}\dfrac{\sin{x}}{\cos{x}} \\&= \dfrac{\dfrac{d}{dx}\sin{x} \times \cos{x}-\sin{x} \times \dfrac{d}{dx}\cos{x}}{\cos^2{x}} &\color{red} \text{quotient rule}\\&= \dfrac{\cos{x} \times \cos{x}-\sin{x} \times (-\sin{x})}{\cos^2{x}} \\&= \dfrac{\cos^2{x} + \sin^2{x}}{\cos^2{x}} \\&= […]