Differentiation and integration are the two fundamental operations in calculus. They are inverse processes, with differentiation finding the rate of change of a function and integration finding the accumulation or total.
Differentiation allows us to analyze how a function changes at any point, useful in finding rates of change, slopes of curves, and optimization problems. Integration enables us to calculate areas under curves, volumes, accumulated quantities, and solve differential equations.
This document provides the essential formulas and techniques for both differentiation and integration, with examples to illustrate their applications.
| Function f(x) | Derivative f'(x) |
|---|---|
| Constant: c | 0 |
| Linear: x | 1 |
| Power: x | nx |
| Exponential: e | e |
| Exponential: a | a ln(a) |
| Logarithmic: ln(x) | 1/x |
| Logarithmic: log(x) | 1/(x ln(a)) |
| Trigonometric: sin(x) | cos(x) |
| Trigonometric: cos(x) | -sin(x) |
| Trigonometric: tan(x) | sec(x) |
| Trigonometric: cot(x) | -csc(x) |
| Trigonometric: sec(x) | sec(x)tan(x) |
| Trigonometric: csc(x) | -csc(x)cot(x) |
| Inverse trigonometric: arcsin(x) | 1/(1-x) |
| Inverse trigonometric: arccos(x) | -1/(1-x) |
| Inverse trigonometric: arctan(x) | 1/(1+x) |
| Hyperbolic: sinh(x) | cosh(x) |
| Hyperbolic: cosh(x) | sinh(x) |
| Hyperbolic: tanh(x) | sech(x) |
Constant Rule: d/dx[cf(x)] = cf'(x)
Sum/Difference Rule: d/dx[f(x) g(x)] = f'(x) g'(x)
Product Rule: d/dx[f(x)g(x)] = f'(x)g(x) + f(x)g'(x)
Example of Product Rule:
Find the derivative of f(x) = xsin(x)
Solution: Using the product rule:
f'(x) = (x)'sin(x) + x(sin(x))' = 2xsin(x) + xcos(x) = x(2sin(x) + xcos(x))
Quotient Rule: d/dx[f(x)/g(x)] = [f'(x)g(x) - f(x)g'(x)]/g(x)
Example of Quotient Rule:
Find the derivative of f(x) = sin(x)/x
Solution: Using the quotient rule:
f'(x) = [(sin(x))'x - sin(x)(x)']/x = [cos(x)x - sin(x)1]/x = [xcos(x) - sin(x)]/x
Chain Rule: d/dx[f(g(x))] = f'(g(x))g'(x)
Example of Chain Rule:
Find the derivative of f(x) = sin(x)
Solution: Using the chain rule with f(u) = sin(u) and g(x) = x:
f'(x) = cos(x)3x
Note: The chain rule is also expressed using Leibniz notation as dy/dx = dy/du du/dx
| Function f(x) | Integral f(x)dx |
|---|---|
| Constant: c | cx + C |
| Power: x (n-1) | x/(n+1) + C |
| Power: x | ln|x| + C |
| Exponential: e | e + C |
| Exponential: a | a/ln(a) + C |
| Logarithmic: ln(x) | xln(x) - x + C |
| Trigonometric: sin(x) | -cos(x) + C |
| Trigonometric: cos(x) | sin(x) + C |
| Trigonometric: tan(x) | -ln|cos(x)| + C |
| Trigonometric: sec(x) | tan(x) + C |
| Trigonometric: csc(x) | -cot(x) + C |
| Trigonometric: sec(x)tan(x) | sec(x) + C |
| Trigonometric: csc(x)cot(x) | -csc(x) + C |
| Inverse trigonometric: 1/(1-x) | arcsin(x) + C |
| Inverse trigonometric: 1/(1+x) | arctan(x) + C |
| Hyperbolic: sinh(x) | cosh(x) + C |
| Hyperbolic: cosh(x) | sinh(x) + C |
| Hyperbolic: sech(x) | tanh(x) + C |
Note: C represents the constant of integration, which is added because the derivative of a constant is zero, so multiple functions can have the same derivative.
Linearity: [cf(x) + cg(x)]dx = cf(x)dx + cg(x)dx
Example of Linearity:
Find (3x + 4sin(x))dx
Solution: Using the linearity property:
(3x + 4sin(x))dx = 3xdx + 4sin(x)dx = 3x/3 + 4(-cos(x)) + C = x - 4cos(x) + C
f(g(x))g'(x)dx = f(u)du, where u = g(x) and du = g'(x)dx
Example of Substitution Method:
Find 2xe^(x)dx
Solution: Let u = x, so du = 2xdx
2xe^(x)dx = e^udu = e^u + C = e^(x) + C
udv = uv - vdu
Example of Integration by Parts:
Find xedx
Solution: Let u = x (so du = dx) and dv = edx (so v = e)
xedx = xe - edx = xe - e + C = e(x-1) + C
1/(ax+b)dx = (1/a)ln|ax+b| + C
1/(x-a)dx = (1/2a)ln|(x-a)/(x+a)| + C
1/(x+a)dx = (1/a)arctan(x/a) + C
1/(a-x)dx = arcsin(x/a) + C
1/(x-a)dx = ln|x+(x-a)| + C
1/(x+a)dx = ln|x+(x+a)| + C
Differentiation has numerous applications in mathematics, science, engineering, and economics:
Integration is widely used to solve problems involving accumulation and summation:
The Fundamental Theorem of Calculus establishes the relationship between differentiation and integration:
First Fundamental Theorem: If F(x) = [a to x] f(t)dt, then F'(x) = f(x)
Second Fundamental Theorem: [a to b] f(x)dx = F(b) - F(a), where F is an antiderivative of f
This theorem shows that differentiation and integration are inverse operations and provides a powerful method for evaluating definite integrals.
Example of the Second Fundamental Theorem:
Evaluate [1 to 2] xdx
Solution: Since x/3 is an antiderivative of x:
[1 to 2] xdx = [x/3]|[1 to 2] = (2/3) - (1/3) = 8/3 - 1/3 = 7/3
Differentiation and integration form the backbone of calculus, a powerful mathematical framework for understanding how quantities change and accumulate. This document has presented the fundamental formulas and techniques of these operations, which serve as essential tools in mathematics, science, engineering, economics, and many other fields.
Mastery of these formulas requires practice and application to various problems. The relationship between differentiation and integration, as expressed in the Fundamental Theorem of Calculus, is not only a beautiful mathematical connection but also a practical tool for solving a wide range of problems.
Whether calculating the rate of change of a physical quantity, finding the optimal dimensions of a structure, computing the area of an irregular region, or modeling complex systems, differentiation and integration provide the mathematical foundation for these calculations.
