Integration - TeachSG

🦉 Integration Rules

1.\,\int k\,\text{d}x = kx +c

2.\,\int x^n\,\text{d}x = \dfrac{x^{n+1}}{n+1} +c, n\ne -1

3.\,\int \sin x\,\text{d}x = -\cos x +c

4.\,\int \cos x\,\text{d}x = \sin x +c

5.\,\int \sec^2 x\,\text{d}x = \tan x +c

6.\,\int e^x\,\text{d}x = e^x +c

7.\,\int \frac{1}{x}\,\text{d}x = \ln x +c

Note: $\int k\text{f}(x)\,\text{d}x=k\times\int \text{f}(x)\,\text{d}x$

🦉 Further Integration Rules

1.\,\int (ax+b)^n\,\text{d}x = \dfrac{(ax+b)^{n+1}}{a(n+1)} +c, n \ne -1

2.\,\int \sin (ax+b)\,\text{d}x = -\dfrac{\cos (ax+b)}{a} +c

3.\,\int \cos (ax+b)\,\text{d}x = \dfrac{\sin (ax+b)}{a} +c

4.\,\int \sec^2 (ax+b)\,\text{d}x = \dfrac{\tan (ax+b)}{a} +c

5.\,\int e^{ax+b}\,\text{d}x = \dfrac{e^{ax+b}}{a} +c

6.\,\int \frac{1}{ax+b}\,\text{d}x = \dfrac{\ln (ax+b)}{a}+c

🦉 Definite Integral

For $\int \text{f}(x) \,\text{d}x = \text{F}(x) + c$,

\displaystyle\int_a^b \text{f}(x) \,\text{d}x = \text{F}(b) -\text{F}(a)

🦉 Area With Respect To $x$-axis Or $y$-axis

\text{For area with respect to } x\text{-axis, } \displaystyle\int_a^b \text{f}(x) \,\text{d}x

\text{For area with respect to } y\text{-axis, } \displaystyle\int_c^d \text{f}(y) \,\text{d}y

Note: For area below the $x$-axis (taken with respect to $x$-axis) or area to the left of the $y$-axis (taken with respect to $y$-axis), it is taken as negative.

🦉 Kinematics

1.\,v=\dfrac{\text{d}s}{\text{d}t}

2.\,a=\dfrac{\text{d}v}{\text{d}t}

3.\,s=\displaystyle\int v\,\text{d}t

4.\,v=\displaystyle\int a\,\text{d}t

Note:
a. velocity, $v$ determines both the speed and the direction
b. $\text{average speed}=\dfrac{\text{total distance}}{\text{total time}}$
c. particle starts from origin, $s = 0$
d. instantaneously at rest, $v = 0$
e. max / min velocity, $a=\dfrac{\text{d}v}{\text{d}t}=0$
f. max / min displacement, $v=\dfrac{\text{d}s}{\text{d}t}=0$