1. Concept Overview
Differentiation tells us how fast a function changes with respect to its variable.
If [y = f(x)], then the derivative is written as:
[f'(x)] or [\dfrac{dy}{dx}]
It represents the rate of change or slope of the tangent to the curve at a point.
2. Standard Derivatives — MUST MEMORIZE
Algebraic + Exponential + Logarithmic + Trigonometric
| Function [f(x)] | Derivative Symbol | Result |
|---|---|---|
| [x^n] | [\dfrac{d}{dx}(x^n)] | [nx^{,n-1}] |
| [e^x] | [\dfrac{d}{dx}(e^x)] | [e^x] |
| [a^x] | [\dfrac{d}{dx}(a^x)] | [a^x \ln(a)] |
| [\ln(x)] | [\dfrac{d}{dx}(\ln(x))] | [\dfrac{1}{x}] |
| [\log_a(x)] | [\dfrac{d}{dx}(\log_a(x))] | [\dfrac{1}{x \ln(a)}] |
| [\sin(x)] | [\dfrac{d}{dx}(\sin(x))] | [\cos(x)] |
| [\cos(x)] | [\dfrac{d}{dx}(\cos(x))] | [-\sin(x)] |
| [\tan(x)] | [\dfrac{d}{dx}(\tan(x))] | [\sec^2(x)] |
| [\cot(x)] | [\dfrac{d}{dx}(\cot(x))] | [-\csc^2(x)] |
| [\sec(x)] | [\dfrac{d}{dx}(\sec(x))] | [\sec(x)\tan(x)] |
| [\csc(x)] | [\dfrac{d}{dx}(\csc(x))] | [-\csc(x)\cot(x)] |
3. Inverse Trigonometric Functions
| Function [f(x)] | Derivative Symbol | Result |
|---|---|---|
| [\sin^{-1}(x)] | [\dfrac{d}{dx}(\sin^{-1}(x))] | [\dfrac{1}{\sqrt{1-x^2}}] |
| [\cos^{-1}(x)] | [\dfrac{d}{dx}(\cos^{-1}(x))] | [-\dfrac{1}{\sqrt{1-x^2}}] |
| [\tan^{-1}(x)] | [\dfrac{d}{dx}(\tan^{-1}(x))] | [\dfrac{1}{1+x^2}] |
| [\cot^{-1}(x)] | [\dfrac{d}{dx}(\cot^{-1}(x))] | [-\dfrac{1}{1+x^2}] |
| [\sec^{-1}(x)] | [\dfrac{d}{dx}(\sec^{-1}(x))] | $ \displaystyle \left\{ \begin{array}{l}\dfrac{1}{{x\sqrt{{{{x}^{2}}-1}}}},\text{ }x>1\\-\dfrac{1}{{x\sqrt{{{{x}^{2}}-1}}}},\text{ }x<-1\end{array} \right.$ |
| [\csc^{-1}(x)] | [\dfrac{d}{dx}(\csc^{-1}(x))] | $ \displaystyle \left\{ \begin{array}{l}-\dfrac{1}{{x\sqrt{{{{x}^{2}}-1}}}},\text{ }x>1\\\dfrac{1}{{x\sqrt{{{{x}^{2}}-1}}}},\text{ }x<-1\end{array} \right.$ |
4. Key Features
✔ Differentiation works term-by-term
✔ No need to expand each time—use rules
✔ Helps calculate slopes, velocity, marginal change, etc.
✔ Essential foundation for further calculus topics