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Belirli Integral Calculator

Reviewed by Calculator Editorial Team

A definite integral represents the area under a curve between two points on the x-axis. This calculator computes the definite integral of a given function between specified limits.

What is a Definite Integral?

The definite integral of a function f(x) with respect to x, from a to b, is written as ∫[a,b] f(x) dx. It calculates the exact area under the curve of f(x) between x = a and x = b.

Definite integrals have many applications in physics, engineering, economics, and other sciences where accumulation of quantities is important.

How to Calculate a Definite Integral

To calculate a definite integral:

  1. Identify the function f(x) you want to integrate
  2. Determine the lower limit (a) and upper limit (b)
  3. Find the antiderivative F(x) of f(x)
  4. Evaluate F(x) at the upper limit and lower limit
  5. Subtract the lower limit evaluation from the upper limit evaluation

The result is the exact area under the curve between the two limits.

Formula

The definite integral of f(x) from a to b is calculated as:

∫[a,b] f(x) dx = F(b) - F(a)

where F(x) is the antiderivative of f(x)

The antiderivative F(x) is found by reversing the differentiation process. Common antiderivatives include:

  • ∫x^n dx = (x^(n+1))/(n+1) + C (for n ≠ -1)
  • ∫sin(x) dx = -cos(x) + C
  • ∫cos(x) dx = sin(x) + C
  • ∫e^x dx = e^x + C

Example Calculation

Let's calculate the definite integral of f(x) = x² from 0 to 2.

  1. Find the antiderivative: ∫x² dx = (x³)/3 + C
  2. Evaluate at upper limit: (2³)/3 = 8/3
  3. Evaluate at lower limit: (0³)/3 = 0
  4. Subtract: (8/3) - 0 = 8/3 ≈ 2.6667

The area under the curve x² from 0 to 2 is 8/3 square units.

FAQ

What is the difference between definite and indefinite integrals?
A definite integral calculates the exact area under a curve between two points, while an indefinite integral finds the antiderivative function.
Can I calculate definite integrals of trigonometric functions?
Yes, this calculator can handle trigonometric functions like sin(x), cos(x), and tan(x).
What if my function doesn't have a known antiderivative?
For functions without elementary antiderivatives, numerical methods or approximations are typically used.
How accurate are the results from this calculator?
The calculator provides exact results when possible, using symbolic computation methods.
Can I use this calculator for physics problems?
Yes, definite integrals are commonly used in physics for calculating work, displacement, and other quantities.